Ignore syntect unmaintained advisories in cargo-deny

chore(tui): Cargo.lock update from main
chore(tui): removed kebab-case info on theme description
2026-02-25 18:23:47 +00:00 · 2026-02-21 14:48:48 -08:00 · 2026-02-21 19:28:15 -03:00 · 2026-02-21 19:28:02 -03:00 · 2026-02-21 19:21:19 -03:00 · 2026-02-21 19:21:19 -03:00
26 changed files with 3774 additions and 490 deletions
--- a/codex-rs/Cargo.lock
+++ b/codex-rs/Cargo.lock
@@ -852,6 +852,15 @@ version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3a8241f3ebb85c056b509d4327ad0358fbbba6ffb340bf388f26350aeda225b1"

+[[package]]
+name = "bincode"
+version = "1.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1f45e9417d87227c7a56d22e471c6206462cba514c7590c09aff4cf6d1ddcad"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "bit-set"
 version = "0.5.3"
@@ -2297,6 +2306,7 @@ dependencies = [
 "strum 0.27.2",
 "strum_macros 0.27.2",
 "supports-color 3.0.2",
+ "syntect",
 "tempfile",
 "textwrap 0.16.2",
 "thiserror 2.0.18",
@@ -2307,8 +2317,7 @@ dependencies = [
 "tracing",
 "tracing-appender",
 "tracing-subscriber",
- "tree-sitter-bash",
- "tree-sitter-highlight",
+ "two-face",
 "unicode-segmentation",
 "unicode-width 0.2.1",
 "url",
@@ -5157,6 +5166,12 @@ dependencies = [
 "vcpkg",
 ]

+[[package]]
+name = "linked-hash-map"
+version = "0.5.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0717cef1bc8b636c6e1c1bbdefc09e6322da8a9321966e8928ef80d20f7f770f"
+
 [[package]]
 name = "linux-keyutils"
 version = "0.2.4"
@@ -5964,6 +5979,28 @@ version = "1.70.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"

+[[package]]
+name = "onig"
+version = "6.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "336b9c63443aceef14bea841b899035ae3abe89b7c486aaf4c5bd8aafedac3f0"
+dependencies = [
+ "bitflags 2.10.0",
+ "libc",
+ "once_cell",
+ "onig_sys",
+]
+
+[[package]]
+name = "onig_sys"
+version = "69.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7f86c6eef3d6df15f23bcfb6af487cbd2fed4e5581d58d5bf1f5f8b7f6727dc"
+dependencies = [
+ "cc",
+ "pkg-config",
+]
+
 [[package]]
 name = "opaque-debug"
 version = "0.3.1"
@@ -6381,6 +6418,19 @@ version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7edddbd0b52d732b21ad9a5fab5c704c14cd949e5e9a1ec5929a24fded1b904c"

+[[package]]
+name = "plist"
+version = "1.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "740ebea15c5d1428f910cd1a5f52cebf8d25006245ed8ade92702f4943d91e07"
+dependencies = [
+ "base64 0.22.1",
+ "indexmap 2.13.0",
+ "quick-xml",
+ "serde",
+ "time",
+]
+
 [[package]]
 name = "png"
 version = "0.18.0"
@@ -8886,6 +8936,27 @@ dependencies = [
 "syn 2.0.114",
 ]

+[[package]]
+name = "syntect"
+version = "5.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "656b45c05d95a5704399aeef6bd0ddec7b2b3531b7c9e900abbf7c4d2190c925"
+dependencies = [
+ "bincode",
+ "flate2",
+ "fnv",
+ "once_cell",
+ "onig",
+ "plist",
+ "regex-syntax 0.8.8",
+ "serde",
+ "serde_derive",
+ "serde_json",
+ "thiserror 2.0.18",
+ "walkdir",
+ "yaml-rust",
+]
+
 [[package]]
 name = "sys-locale"
 version = "0.3.2"
@@ -9622,18 +9693,6 @@ dependencies = [
 "tree-sitter-language",
 ]

-[[package]]
-name = "tree-sitter-highlight"
-version = "0.25.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "adc5f880ad8d8f94e88cb81c3557024cf1a8b75e3b504c50481ed4f5a6006ff3"
-dependencies = [
- "regex",
- "streaming-iterator",
- "thiserror 2.0.18",
- "tree-sitter",
-]
-
 [[package]]
 name = "tree-sitter-language"
 version = "0.1.7"
@@ -9701,6 +9760,17 @@ dependencies = [
 "utf-8",
 ]

+[[package]]
+name = "two-face"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b285c51f8a6ade109ed4566d33ac4fb289fb5d6cf87ed70908a5eaf65e948e34"
+dependencies = [
+ "serde",
+ "serde_derive",
+ "syntect",
+]
+
 [[package]]
 name = "type-map"
 version = "0.5.1"
@@ -10965,6 +11035,15 @@ dependencies = [
 "lzma-sys",
 ]

+[[package]]
+name = "yaml-rust"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56c1936c4cc7a1c9ab21a1ebb602eb942ba868cbd44a99cb7cdc5892335e1c85"
+dependencies = [
+ "linked-hash-map",
+]
+
 [[package]]
 name = "yansi"
 version = "1.0.1"
--- a/codex-rs/Cargo.toml
+++ b/codex-rs/Cargo.toml
@@ -276,7 +276,7 @@ tracing-subscriber = "0.3.22"
 tracing-test = "0.2.5"
 tree-sitter = "0.25.10"
 tree-sitter-bash = "0.25"
-tree-sitter-highlight = "0.25.10"
+syntect = "5"
 ts-rs = "11"
 tungstenite = { version = "0.27.0", features = ["deflate", "proxy"] }
 uds_windows = "1.1.0"
--- a/codex-rs/core/config.schema.json
+++ b/codex-rs/core/config.schema.json
@@ -49,23 +49,17 @@
      "oneOf": [
        {
          "description": "Auto-detect: disable alternate screen in Zellij, enable elsewhere.",
-          "enum": [
-            "auto"
-          ],
+          "enum": ["auto"],
          "type": "string"
        },
        {
          "description": "Always use alternate screen (original behavior).",
-          "enum": [
-            "always"
-          ],
+          "enum": ["always"],
          "type": "string"
        },
        {
          "description": "Never use alternate screen (inline mode only).",
-          "enum": [
-            "never"
-          ],
+          "enum": ["never"],
          "type": "string"
        }
      ]
@@ -122,11 +116,7 @@
      "type": "object"
    },
    "AppToolApproval": {
-      "enum": [
-        "auto",
-        "prompt",
-        "approve"
-      ],
+      "enum": ["auto", "prompt", "approve"],
      "type": "string"
    },
    "AppToolConfig": {
@@ -197,23 +187,17 @@
      "oneOf": [
        {
          "description": "Under this policy, only \"known safe\" commands—as determined by `is_safe_command()`—that **only read files** are auto‑approved. Everything else will ask the user to approve.",
-          "enum": [
-            "untrusted"
-          ],
+          "enum": ["untrusted"],
          "type": "string"
        },
        {
          "description": "DEPRECATED: *All* commands are auto‑approved, but they are expected to run inside a sandbox where network access is disabled and writes are confined to a specific set of paths. If the command fails, it will be escalated to the user to approve execution without a sandbox. Prefer `OnRequest` for interactive runs or `Never` for non-interactive runs.",
-          "enum": [
-            "on-failure"
-          ],
+          "enum": ["on-failure"],
          "type": "string"
        },
        {
          "description": "The model decides when to ask the user for approval.",
-          "enum": [
-            "on-request"
-          ],
+          "enum": ["on-request"],
          "type": "string"
        },
        {
@@ -224,16 +208,12 @@
              "$ref": "#/definitions/RejectConfig"
            }
          },
-          "required": [
-            "reject"
-          ],
+          "required": ["reject"],
          "type": "object"
        },
        {
          "description": "Never ask the user to approve commands. Failures are immediately returned to the model, and never escalated to the user for approval.",
-          "enum": [
-            "never"
-          ],
+          "enum": ["never"],
          "type": "string"
        }
      ]
@@ -243,30 +223,22 @@
      "oneOf": [
        {
          "description": "Persist credentials in CODEX_HOME/auth.json.",
-          "enum": [
-            "file"
-          ],
+          "enum": ["file"],
          "type": "string"
        },
        {
          "description": "Persist credentials in the keyring. Fail if unavailable.",
-          "enum": [
-            "keyring"
-          ],
+          "enum": ["keyring"],
          "type": "string"
        },
        {
          "description": "Use keyring when available; otherwise, fall back to a file in CODEX_HOME.",
-          "enum": [
-            "auto"
-          ],
+          "enum": ["auto"],
          "type": "string"
        },
        {
          "description": "Store credentials in memory only for the current process.",
-          "enum": [
-            "ephemeral"
-          ],
+          "enum": ["ephemeral"],
          "type": "string"
        }
      ]
@@ -520,10 +492,7 @@
      "type": "object"
    },
    "ForcedLoginMethod": {
-      "enum": [
-        "chatgpt",
-        "api"
-      ],
+      "enum": ["chatgpt", "api"],
      "type": "string"
    },
    "GhostSnapshotToml": {
@@ -565,25 +534,19 @@
          "description": "If true, history entries will not be written to disk."
        }
      },
-      "required": [
-        "persistence"
-      ],
+      "required": ["persistence"],
      "type": "object"
    },
    "HistoryPersistence": {
      "oneOf": [
        {
          "description": "Save all history entries to disk.",
-          "enum": [
-            "save-all"
-          ],
+          "enum": ["save-all"],
          "type": "string"
        },
        {
          "description": "Do not write history to disk.",
-          "enum": [
-            "none"
-          ],
+          "enum": ["none"],
          "type": "string"
        }
      ]
@@ -708,16 +671,11 @@
          "description": "Which wire protocol this provider expects."
        }
      },
-      "required": [
-        "name"
-      ],
+      "required": ["name"],
      "type": "object"
    },
    "NetworkModeSchema": {
-      "enum": [
-        "limited",
-        "full"
-      ],
+      "enum": ["limited", "full"],
      "type": "string"
    },
    "NetworkToml": {
@@ -815,11 +773,7 @@
      "type": "object"
    },
    "NotificationMethod": {
-      "enum": [
-        "auto",
-        "osc9",
-        "bel"
-      ],
+      "enum": ["auto", "osc9", "bel"],
      "type": "string"
    },
    "Notifications": {
@@ -840,23 +794,17 @@
      "oneOf": [
        {
          "description": "`Keyring` when available; otherwise, `File`. Credentials stored in the keyring will only be readable by Codex unless the user explicitly grants access via OS-level keyring access.",
-          "enum": [
-            "auto"
-          ],
+          "enum": ["auto"],
          "type": "string"
        },
        {
          "description": "CODEX_HOME/.credentials.json This file will be readable to Codex and other applications running as the same user.",
-          "enum": [
-            "file"
-          ],
+          "enum": ["file"],
          "type": "string"
        },
        {
          "description": "Keyring when available, otherwise fail.",
-          "enum": [
-            "keyring"
-          ],
+          "enum": ["keyring"],
          "type": "string"
        }
      ]
@@ -904,10 +852,7 @@
      "description": "Which OTEL exporter to use.",
      "oneOf": [
        {
-          "enum": [
-            "none",
-            "statsig"
-          ],
+          "enum": ["none", "statsig"],
          "type": "string"
        },
        {
@@ -938,16 +883,11 @@
                  "default": null
                }
              },
-              "required": [
-                "endpoint",
-                "protocol"
-              ],
+              "required": ["endpoint", "protocol"],
              "type": "object"
            }
          },
-          "required": [
-            "otlp-http"
-          ],
+          "required": ["otlp-http"],
          "type": "object"
        },
        {
@@ -975,15 +915,11 @@
                  "default": null
                }
              },
-              "required": [
-                "endpoint"
-              ],
+              "required": ["endpoint"],
              "type": "object"
            }
          },
-          "required": [
-            "otlp-grpc"
-          ],
+          "required": ["otlp-grpc"],
          "type": "object"
        }
      ]
@@ -992,16 +928,12 @@
      "oneOf": [
        {
          "description": "Binary payload",
-          "enum": [
-            "binary"
-          ],
+          "enum": ["binary"],
          "type": "string"
        },
        {
          "description": "JSON payload",
-          "enum": [
-            "json"
-          ],
+          "enum": ["json"],
          "type": "string"
        }
      ]
@@ -1036,11 +968,7 @@
      "type": "object"
    },
    "Personality": {
-      "enum": [
-        "none",
-        "friendly",
-        "pragmatic"
-      ],
+      "enum": ["none", "friendly", "pragmatic"],
      "type": "string"
    },
    "ProjectConfig": {
@@ -1155,32 +1083,19 @@
    },
    "ReasoningEffort": {
      "description": "See https://platform.openai.com/docs/guides/reasoning?api-mode=responses#get-started-with-reasoning",
-      "enum": [
-        "none",
-        "minimal",
-        "low",
-        "medium",
-        "high",
-        "xhigh"
-      ],
+      "enum": ["none", "minimal", "low", "medium", "high", "xhigh"],
      "type": "string"
    },
    "ReasoningSummary": {
      "description": "A summary of the reasoning performed by the model. This can be useful for debugging and understanding the model's reasoning process. See https://platform.openai.com/docs/guides/reasoning?api-mode=responses#reasoning-summaries",
      "oneOf": [
        {
-          "enum": [
-            "auto",
-            "concise",
-            "detailed"
-          ],
+          "enum": ["auto", "concise", "detailed"],
          "type": "string"
        },
        {
          "description": "Option to disable reasoning summaries.",
-          "enum": [
-            "none"
-          ],
+          "enum": ["none"],
          "type": "string"
        }
      ]
@@ -1200,19 +1115,11 @@
          "type": "boolean"
        }
      },
-      "required": [
-        "mcp_elicitations",
-        "rules",
-        "sandbox_approval"
-      ],
+      "required": ["mcp_elicitations", "rules", "sandbox_approval"],
      "type": "object"
    },
    "SandboxMode": {
-      "enum": [
-        "read-only",
-        "workspace-write",
-        "danger-full-access"
-      ],
+      "enum": ["read-only", "workspace-write", "danger-full-access"],
      "type": "string"
    },
    "SandboxWorkspaceWrite": {
@@ -1244,23 +1151,17 @@
      "oneOf": [
        {
          "description": "\"Core\" environment variables for the platform. On UNIX, this would include HOME, LOGNAME, PATH, SHELL, and USER, among others.",
-          "enum": [
-            "core"
-          ],
+          "enum": ["core"],
          "type": "string"
        },
        {
          "description": "Inherits the full environment from the parent process.",
-          "enum": [
-            "all"
-          ],
+          "enum": ["all"],
          "type": "string"
        },
        {
          "description": "Do not inherit any environment variables from the parent process.",
-          "enum": [
-            "none"
-          ],
+          "enum": ["none"],
          "type": "string"
        }
      ]
@@ -1311,10 +1212,7 @@
          "$ref": "#/definitions/AbsolutePathBuf"
        }
      },
-      "required": [
-        "enabled",
-        "path"
-      ],
+      "required": ["enabled", "path"],
      "type": "object"
    },
    "SkillsConfig": {
@@ -1346,10 +1244,7 @@
    },
    "TrustLevel": {
      "description": "Represents the trust level for a project directory. This determines the approval policy and sandbox mode applied.",
-      "enum": [
-        "trusted",
-        "untrusted"
-      ],
+      "enum": ["trusted", "untrusted"],
      "type": "string"
    },
    "Tui": {
@@ -1400,6 +1295,11 @@
            "type": "string"
          },
          "type": "array"
+        },
+        "theme": {
+          "default": null,
+          "description": "Syntax highlighting theme name.\n\nWhen set, overrides automatic light/dark theme detection. Use `/theme` in the TUI or see `$CODEX_HOME/themes` for custom themes.",
+          "type": "string"
        }
      },
      "type": "object"
@@ -1407,45 +1307,27 @@
    "UriBasedFileOpener": {
      "oneOf": [
        {
-          "enum": [
-            "vscode",
-            "vscode-insiders",
-            "windsurf",
-            "cursor"
-          ],
+          "enum": ["vscode", "vscode-insiders", "windsurf", "cursor"],
          "type": "string"
        },
        {
          "description": "Option to disable the URI-based file opener.",
-          "enum": [
-            "none"
-          ],
+          "enum": ["none"],
          "type": "string"
        }
      ]
    },
    "Verbosity": {
      "description": "Controls output length/detail on GPT-5 models via the Responses API. Serialized with lowercase values to match the OpenAI API.",
-      "enum": [
-        "low",
-        "medium",
-        "high"
-      ],
+      "enum": ["low", "medium", "high"],
      "type": "string"
    },
    "WebSearchMode": {
-      "enum": [
-        "disabled",
-        "cached",
-        "live"
-      ],
+      "enum": ["disabled", "cached", "live"],
      "type": "string"
    },
    "WindowsSandboxModeToml": {
-      "enum": [
-        "elevated",
-        "unelevated"
-      ],
+      "enum": ["elevated", "unelevated"],
      "type": "string"
    },
    "WindowsToml": {
@@ -1462,9 +1344,7 @@
      "oneOf": [
        {
          "description": "The Responses API exposed by OpenAI at `/v1/responses`.",
-          "enum": [
-            "responses"
-          ],
+          "enum": ["responses"],
          "type": "string"
        }
      ]
@@ -2063,4 +1943,5 @@
  },
  "title": "ConfigToml",
  "type": "object"
-}
+}
+
--- a/codex-rs/core/src/config/edit.rs
+++ b/codex-rs/core/src/config/edit.rs
@@ -55,6 +55,14 @@ pub enum ConfigEdit {
    ClearPath { segments: Vec<String> },
 }

+/// Produces a config edit that sets `[tui] theme = "<name>"`.
+pub fn syntax_theme_edit(name: &str) -> ConfigEdit {
+    ConfigEdit::SetPath {
+        segments: vec!["tui".to_string(), "theme".to_string()],
+        value: value(name.to_string()),
+    }
+}
+
 pub fn status_line_items_edit(items: &[String]) -> ConfigEdit {
    let mut array = toml_edit::Array::new();
    for item in items {
--- a/codex-rs/core/src/config/mod.rs
+++ b/codex-rs/core/src/config/mod.rs
@@ -278,6 +278,9 @@ pub struct Config {
    /// `current-dir`.
    pub tui_status_line: Option<Vec<String>>,

+    /// Syntax highlighting theme override (kebab-case name).
+    pub tui_theme: Option<String>,
+
    /// The directory that should be treated as the current working directory
    /// for the session. All relative paths inside the business-logic layer are
    /// resolved against this path.
@@ -2120,6 +2123,7 @@ impl Config {
                .map(|t| t.alternate_screen)
                .unwrap_or_default(),
            tui_status_line: cfg.tui.as_ref().and_then(|t| t.status_line.clone()),
+            tui_theme: cfg.tui.as_ref().and_then(|t| t.theme.clone()),
            otel: {
                let t: OtelConfigToml = cfg.otel.unwrap_or_default();
                let log_user_prompt = t.log_user_prompt.unwrap_or(false);
@@ -2518,6 +2522,30 @@ allowed_domains = ["openai.com"]
        Ok(())
    }

+    #[test]
+    fn tui_theme_deserializes_from_toml() {
+        let cfg = r#"
+[tui]
+theme = "dracula"
+"#;
+        let parsed =
+            toml::from_str::<ConfigToml>(cfg).expect("TOML deserialization should succeed");
+        assert_eq!(
+            parsed.tui.as_ref().and_then(|t| t.theme.as_deref()),
+            Some("dracula"),
+        );
+    }
+
+    #[test]
+    fn tui_theme_defaults_to_none() {
+        let cfg = r#"
+[tui]
+"#;
+        let parsed =
+            toml::from_str::<ConfigToml>(cfg).expect("TOML deserialization should succeed");
+        assert_eq!(parsed.tui.as_ref().and_then(|t| t.theme.as_deref()), None);
+    }
+
    #[test]
    fn tui_config_missing_notifications_field_defaults_to_enabled() {
        let cfg = r#"
@@ -2537,6 +2565,7 @@ allowed_domains = ["openai.com"]
                show_tooltips: true,
                alternate_screen: AltScreenMode::Auto,
                status_line: None,
+                theme: None,
            }
        );
    }
@@ -4646,6 +4675,7 @@ model_verbosity = "high"
                feedback_enabled: true,
                tui_alternate_screen: AltScreenMode::Auto,
                tui_status_line: None,
+                tui_theme: None,
                otel: OtelConfig::default(),
            },
            o3_profile_config
@@ -4768,6 +4798,7 @@ model_verbosity = "high"
            feedback_enabled: true,
            tui_alternate_screen: AltScreenMode::Auto,
            tui_status_line: None,
+            tui_theme: None,
            otel: OtelConfig::default(),
        };

@@ -4888,6 +4919,7 @@ model_verbosity = "high"
            feedback_enabled: true,
            tui_alternate_screen: AltScreenMode::Auto,
            tui_status_line: None,
+            tui_theme: None,
            otel: OtelConfig::default(),
        };

@@ -4994,6 +5026,7 @@ model_verbosity = "high"
            feedback_enabled: true,
            tui_alternate_screen: AltScreenMode::Auto,
            tui_status_line: None,
+            tui_theme: None,
            otel: OtelConfig::default(),
        };

--- a/codex-rs/core/src/config/types.rs
+++ b/codex-rs/core/src/config/types.rs
@@ -681,6 +681,13 @@ pub struct Tui {
    /// `current-dir`.
    #[serde(default)]
    pub status_line: Option<Vec<String>>,
+
+    /// Syntax highlighting theme name (kebab-case).
+    ///
+    /// When set, overrides automatic light/dark theme detection.
+    /// Use `/theme` in the TUI or see `$CODEX_HOME/themes` for custom themes.
+    #[serde(default)]
+    pub theme: Option<String>,
 }

 const fn default_true() -> bool {
--- a/codex-rs/deny.toml
+++ b/codex-rs/deny.toml
@@ -73,6 +73,8 @@ ignore = [
    { id = "RUSTSEC-2024-0388", reason = "derivative is unmaintained; pulled in via starlark v0.13.0 used by execpolicy/cli/core; no fixed release yet" },
    { id = "RUSTSEC-2025-0057", reason = "fxhash is unmaintained; pulled in via starlark_map/starlark v0.13.0 used by execpolicy/cli/core; no fixed release yet" },
    { id = "RUSTSEC-2024-0436", reason = "paste is unmaintained; pulled in via ratatui/rmcp/starlark used by tui/execpolicy; no fixed release yet" },
+    { id = "RUSTSEC-2024-0320", reason = "yaml-rust is unmaintained; pulled in via syntect/two-face used by tui syntax highlighting; no safe upgrade is available" },
+    { id = "RUSTSEC-2025-0141", reason = "bincode is unmaintained; pulled in via syntect/two-face used by tui syntax highlighting; no safe upgrade is available" },
    # TODO(joshka, nornagon): remove this exception when once we update the ratatui fork to a version that uses lru 0.13+.
    { id = "RUSTSEC-2026-0002", reason = "lru 0.12.5 is pulled in via ratatui fork; cannot upgrade until the fork is updated" },
 ]
--- a/codex-rs/tui/Cargo.toml
+++ b/codex-rs/tui/Cargo.toml
@@ -93,8 +93,8 @@ toml = { workspace = true }
 tracing = { workspace = true, features = ["log"] }
 tracing-appender = { workspace = true }
 tracing-subscriber = { workspace = true, features = ["env-filter"] }
-tree-sitter-bash = { workspace = true }
-tree-sitter-highlight = { workspace = true }
+syntect = "5"
+two-face = { version = "0.5", default-features = false, features = ["syntect-default-onig"] }
 unicode-segmentation = { workspace = true }
 unicode-width = { workspace = true }
 url = { workspace = true }
--- a/codex-rs/tui/src/app.rs
+++ b/codex-rs/tui/src/app.rs
@@ -2605,6 +2605,34 @@ impl App {
            AppEvent::StatusLineSetupCancelled => {
                self.chat_widget.cancel_status_line_setup();
            }
+            AppEvent::SyntaxThemeSelected { name } => {
+                let edit = codex_core::config::edit::syntax_theme_edit(&name);
+                let apply_result = ConfigEditsBuilder::new(&self.config.codex_home)
+                    .with_edits([edit])
+                    .apply()
+                    .await;
+                match apply_result {
+                    Ok(()) => {
+                        // Ensure the selected theme is active in the current
+                        // session.  The preview callback covers arrow-key
+                        // navigation, but if the user presses Enter without
+                        // navigating, the runtime theme must still be applied.
+                        if let Some(theme) = crate::render::highlight::resolve_theme_by_name(
+                            &name,
+                            Some(&self.config.codex_home),
+                        ) {
+                            crate::render::highlight::set_syntax_theme(theme);
+                        }
+                        self.sync_tui_theme_selection(name);
+                    }
+                    Err(err) => {
+                        self.restore_runtime_theme_from_config();
+                        tracing::error!(error = %err, "failed to persist theme selection");
+                        self.chat_widget
+                            .add_error_message(format!("Failed to save theme: {err}"));
+                    }
+                }
+            }
        }
        Ok(AppRunControl::Continue)
    }
@@ -2783,6 +2811,29 @@ impl App {
        self.chat_widget.set_personality(personality);
    }

+    fn sync_tui_theme_selection(&mut self, name: String) {
+        self.config.tui_theme = Some(name.clone());
+        self.chat_widget.set_tui_theme(Some(name));
+    }
+
+    fn restore_runtime_theme_from_config(&self) {
+        if let Some(name) = self.config.tui_theme.as_deref()
+            && let Some(theme) =
+                crate::render::highlight::resolve_theme_by_name(name, Some(&self.config.codex_home))
+        {
+            crate::render::highlight::set_syntax_theme(theme);
+            return;
+        }
+
+        let auto_theme_name = crate::render::highlight::adaptive_default_theme_name();
+        if let Some(theme) = crate::render::highlight::resolve_theme_by_name(
+            auto_theme_name,
+            Some(&self.config.codex_home),
+        ) {
+            crate::render::highlight::set_syntax_theme(theme);
+        }
+    }
+
    fn personality_label(personality: Personality) -> &'static str {
        match personality {
            Personality::None => "None",
@@ -3655,6 +3706,19 @@ mod tests {
        Ok(())
    }

+    #[tokio::test]
+    async fn sync_tui_theme_selection_updates_chat_widget_config_copy() {
+        let mut app = make_test_app().await;
+
+        app.sync_tui_theme_selection("dracula".to_string());
+
+        assert_eq!(app.config.tui_theme.as_deref(), Some("dracula"));
+        assert_eq!(
+            app.chat_widget.config_ref().tui_theme.as_deref(),
+            Some("dracula")
+        );
+    }
+
    #[tokio::test]
    async fn backtrack_selection_with_duplicate_history_targets_unique_turn() {
        let (mut app, _app_event_rx, mut op_rx) = make_test_app_with_channels().await;
--- a/codex-rs/tui/src/app_event.rs
+++ b/codex-rs/tui/src/app_event.rs
@@ -360,6 +360,11 @@ pub(crate) enum AppEvent {
    },
    /// Dismiss the status-line setup UI without changing config.
    StatusLineSetupCancelled,
+
+    /// Apply a user-confirmed syntax theme selection.
+    SyntaxThemeSelected {
+        name: String,
+    },
 }

 /// The exit strategy requested by the UI layer.
--- a/codex-rs/tui/src/bottom_pane/list_selection_view.rs
+++ b/codex-rs/tui/src/bottom_pane/list_selection_view.rs
@@ -33,9 +33,76 @@ use super::selection_popup_common::render_rows_stable_col_widths;
 use super::selection_popup_common::render_rows_with_col_width_mode;
 use unicode_width::UnicodeWidthStr;

+/// Minimum list width (in content columns) required before the side-by-side
+/// layout is activated. Keeps the list usable even when sharing horizontal
+/// space with the side content panel.
+const MIN_LIST_WIDTH_FOR_SIDE: u16 = 40;
+
+/// Horizontal gap (in columns) between the list area and the side content
+/// panel when side-by-side layout is active.
+const SIDE_CONTENT_GAP: u16 = 2;
+
+/// Shared menu-surface horizontal inset (2 cells per side) used by selection popups.
+const MENU_SURFACE_HORIZONTAL_INSET: u16 = 4;
+
+/// Controls how the side content panel is sized relative to the popup width.
+///
+/// When the computed side width falls below `side_content_min_width` or the
+/// remaining list area would be narrower than [`MIN_LIST_WIDTH_FOR_SIDE`], the
+/// side-by-side layout is abandoned and the stacked fallback is used instead.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub(crate) enum SideContentWidth {
+    /// Fixed number of columns.  `Fixed(0)` disables side content entirely.
+    Fixed(u16),
+    /// Exact 50/50 split of the content area (minus the inter-column gap).
+    Half,
+}
+
+impl Default for SideContentWidth {
+    fn default() -> Self {
+        Self::Fixed(0)
+    }
+}
+
+/// Returns the popup content width after subtracting the shared menu-surface
+/// horizontal inset (2 columns on each side).
+pub(crate) fn popup_content_width(total_width: u16) -> u16 {
+    total_width.saturating_sub(MENU_SURFACE_HORIZONTAL_INSET)
+}
+
+/// Returns side-by-side layout widths as `(list_width, side_width)` when the
+/// layout can fit. Returns `None` when the side panel is disabled/too narrow or
+/// when the remaining list width would become unusably small.
+pub(crate) fn side_by_side_layout_widths(
+    content_width: u16,
+    side_content_width: SideContentWidth,
+    side_content_min_width: u16,
+) -> Option<(u16, u16)> {
+    let side_width = match side_content_width {
+        SideContentWidth::Fixed(0) => return None,
+        SideContentWidth::Fixed(width) => width,
+        SideContentWidth::Half => content_width.saturating_sub(SIDE_CONTENT_GAP) / 2,
+    };
+    if side_width < side_content_min_width {
+        return None;
+    }
+    let list_width = content_width.saturating_sub(SIDE_CONTENT_GAP + side_width);
+    (list_width >= MIN_LIST_WIDTH_FOR_SIDE).then_some((list_width, side_width))
+}
+
 /// One selectable item in the generic selection list.
 pub(crate) type SelectionAction = Box<dyn Fn(&AppEventSender) + Send + Sync>;

+/// Callback invoked whenever the highlighted item changes (arrow keys, search
+/// filter, number-key jump).  Receives the *actual* index into the unfiltered
+/// `items` list and the event sender.  Used by the theme picker for live preview.
+pub(crate) type OnSelectionChangedCallback =
+    Option<Box<dyn Fn(usize, &AppEventSender) + Send + Sync>>;
+
+/// Callback invoked when the picker is dismissed without accepting (Esc or
+/// Ctrl+C).  Used by the theme picker to restore the pre-open theme.
+pub(crate) type OnCancelCallback = Option<Box<dyn Fn(&AppEventSender) + Send + Sync>>;
+
 /// One row in a [`ListSelectionView`] selection list.
 ///
 /// This is the source-of-truth model for row state before filtering and
@@ -79,6 +146,28 @@ pub(crate) struct SelectionViewParams {
    pub col_width_mode: ColumnWidthMode,
    pub header: Box<dyn Renderable>,
    pub initial_selected_idx: Option<usize>,
+
+    /// Rich content rendered beside (wide terminals) or below (narrow terminals)
+    /// the list items, inside the bordered menu surface. Used by the theme picker
+    /// to show a syntax-highlighted preview.
+    pub side_content: Box<dyn Renderable>,
+
+    /// Width mode for side content when side-by-side layout is active.
+    pub side_content_width: SideContentWidth,
+
+    /// Minimum side panel width required before side-by-side layout activates.
+    pub side_content_min_width: u16,
+
+    /// Optional fallback content rendered when side-by-side does not fit.
+    /// When absent, `side_content` is reused.
+    pub stacked_side_content: Option<Box<dyn Renderable>>,
+
+    /// Called when the highlighted item changes (navigation, filter, number-key).
+    /// Receives the *actual* item index, not the filtered/visible index.
+    pub on_selection_changed: OnSelectionChangedCallback,
+
+    /// Called when the picker is dismissed via Esc/Ctrl+C without selecting.
+    pub on_cancel: OnCancelCallback,
 }

 impl Default for SelectionViewParams {
@@ -95,6 +184,12 @@ impl Default for SelectionViewParams {
            col_width_mode: ColumnWidthMode::AutoVisible,
            header: Box::new(()),
            initial_selected_idx: None,
+            side_content: Box::new(()),
+            side_content_width: SideContentWidth::default(),
+            side_content_min_width: 0,
+            stacked_side_content: None,
+            on_selection_changed: None,
+            on_cancel: None,
        }
    }
 }
@@ -120,6 +215,16 @@ pub(crate) struct ListSelectionView {
    last_selected_actual_idx: Option<usize>,
    header: Box<dyn Renderable>,
    initial_selected_idx: Option<usize>,
+    side_content: Box<dyn Renderable>,
+    side_content_width: SideContentWidth,
+    side_content_min_width: u16,
+    stacked_side_content: Option<Box<dyn Renderable>>,
+
+    /// Called when the highlighted item changes (navigation, filter, number-key).
+    on_selection_changed: OnSelectionChangedCallback,
+
+    /// Called when the picker is dismissed via Esc/Ctrl+C without selecting.
+    on_cancel: OnCancelCallback,
 }

 impl ListSelectionView {
@@ -161,6 +266,12 @@ impl ListSelectionView {
            last_selected_actual_idx: None,
            header,
            initial_selected_idx: params.initial_selected_idx,
+            side_content: params.side_content,
+            side_content_width: params.side_content_width,
+            side_content_min_width: params.side_content_min_width,
+            stacked_side_content: params.stacked_side_content,
+            on_selection_changed: params.on_selection_changed,
+            on_cancel: params.on_cancel,
        };
        s.apply_filter();
        s
@@ -174,11 +285,15 @@ impl ListSelectionView {
        MAX_POPUP_ROWS.min(len.max(1))
    }

-    fn apply_filter(&mut self) {
-        let previously_selected = self
-            .state
+    fn selected_actual_idx(&self) -> Option<usize> {
+        self.state
            .selected_idx
            .and_then(|visible_idx| self.filtered_indices.get(visible_idx).copied())
+    }
+
+    fn apply_filter(&mut self) {
+        let previously_selected = self
+            .selected_actual_idx()
            .or_else(|| {
                (!self.is_searchable)
                    .then(|| self.items.iter().position(|item| item.is_current))
@@ -222,6 +337,13 @@ impl ListSelectionView {
        let visible = Self::max_visible_rows(len);
        self.state.clamp_selection(len);
        self.state.ensure_visible(len, visible);
+
+        // Notify the callback when filtering changes the selected actual item
+        // so live preview stays in sync (e.g. typing in the theme picker).
+        let new_actual = self.selected_actual_idx();
+        if new_actual != previously_selected {
+            self.fire_selection_changed();
+        }
    }

    fn build_rows(&self) -> Vec<GenericDisplayRow> {
@@ -273,19 +395,35 @@ impl ListSelectionView {
    }

    fn move_up(&mut self) {
+        let before = self.selected_actual_idx();
        let len = self.visible_len();
        self.state.move_up_wrap(len);
        let visible = Self::max_visible_rows(len);
        self.state.ensure_visible(len, visible);
        self.skip_disabled_up();
+        if self.selected_actual_idx() != before {
+            self.fire_selection_changed();
+        }
    }

    fn move_down(&mut self) {
+        let before = self.selected_actual_idx();
        let len = self.visible_len();
        self.state.move_down_wrap(len);
        let visible = Self::max_visible_rows(len);
        self.state.ensure_visible(len, visible);
        self.skip_disabled_down();
+        if self.selected_actual_idx() != before {
+            self.fire_selection_changed();
+        }
+    }
+
+    fn fire_selection_changed(&self) {
+        if let Some(cb) = &self.on_selection_changed
+            && let Some(actual) = self.selected_actual_idx()
+        {
+            cb(actual, &self.app_event_tx);
+        }
    }

    fn accept(&mut self) {
@@ -310,6 +448,9 @@ impl ListSelectionView {
                self.complete = true;
            }
        } else if selected_item.is_none() {
+            if let Some(cb) = &self.on_cancel {
+                cb(&self.app_event_tx);
+            }
            self.complete = true;
        }
    }
@@ -328,6 +469,63 @@ impl ListSelectionView {
        total_width.saturating_sub(2)
    }

+    fn clear_to_terminal_bg(buf: &mut Buffer, area: Rect) {
+        let buf_area = buf.area();
+        let min_x = area.x.max(buf_area.x);
+        let min_y = area.y.max(buf_area.y);
+        let max_x = area
+            .x
+            .saturating_add(area.width)
+            .min(buf_area.x.saturating_add(buf_area.width));
+        let max_y = area
+            .y
+            .saturating_add(area.height)
+            .min(buf_area.y.saturating_add(buf_area.height));
+        for y in min_y..max_y {
+            for x in min_x..max_x {
+                buf[(x, y)]
+                    .set_symbol(" ")
+                    .set_style(ratatui::style::Style::reset());
+            }
+        }
+    }
+
+    fn force_bg_to_terminal_bg(buf: &mut Buffer, area: Rect) {
+        let buf_area = buf.area();
+        let min_x = area.x.max(buf_area.x);
+        let min_y = area.y.max(buf_area.y);
+        let max_x = area
+            .x
+            .saturating_add(area.width)
+            .min(buf_area.x.saturating_add(buf_area.width));
+        let max_y = area
+            .y
+            .saturating_add(area.height)
+            .min(buf_area.y.saturating_add(buf_area.height));
+        for y in min_y..max_y {
+            for x in min_x..max_x {
+                buf[(x, y)].set_bg(ratatui::style::Color::Reset);
+            }
+        }
+    }
+
+    fn stacked_side_content(&self) -> &dyn Renderable {
+        self.stacked_side_content
+            .as_deref()
+            .unwrap_or_else(|| self.side_content.as_ref())
+    }
+
+    /// Returns `Some(side_width)` when the content area is wide enough for a
+    /// side-by-side layout (list + gap + side panel), `None` otherwise.
+    fn side_layout_width(&self, content_width: u16) -> Option<u16> {
+        side_by_side_layout_widths(
+            content_width,
+            self.side_content_width,
+            self.side_content_min_width,
+        )
+        .map(|(_, side_width)| side_width)
+    }
+
    fn skip_disabled_down(&mut self) {
        let len = self.visible_len();
        for _ in 0..len {
@@ -469,6 +667,9 @@ impl BottomPaneView for ListSelectionView {
    }

    fn on_ctrl_c(&mut self) -> CancellationEvent {
+        if let Some(cb) = &self.on_cancel {
+            cb(&self.app_event_tx);
+        }
        self.complete = true;
        CancellationEvent::Handled
    }
@@ -476,38 +677,59 @@ impl BottomPaneView for ListSelectionView {

 impl Renderable for ListSelectionView {
    fn desired_height(&self, width: u16) -> u16 {
-        // Measure wrapped height for up to MAX_POPUP_ROWS items at the given width.
-        // Build the same display rows used by the renderer so wrapping math matches.
+        // Inner content width after menu surface horizontal insets (2 per side).
+        let inner_width = popup_content_width(width);
+
+        // When side-by-side is active, measure the list at the reduced width
+        // that accounts for the gap and side panel.
+        let effective_rows_width = if let Some(side_w) = self.side_layout_width(inner_width) {
+            Self::rows_width(width).saturating_sub(SIDE_CONTENT_GAP + side_w)
+        } else {
+            Self::rows_width(width)
+        };
+
+        // Measure wrapped height for up to MAX_POPUP_ROWS items.
        let rows = self.build_rows();
-        let rows_width = Self::rows_width(width);
        let rows_height = match self.col_width_mode {
            ColumnWidthMode::AutoVisible => measure_rows_height(
                &rows,
                &self.state,
                MAX_POPUP_ROWS,
-                rows_width.saturating_add(1),
+                effective_rows_width.saturating_add(1),
            ),
            ColumnWidthMode::AutoAllRows => measure_rows_height_stable_col_widths(
                &rows,
                &self.state,
                MAX_POPUP_ROWS,
-                rows_width.saturating_add(1),
+                effective_rows_width.saturating_add(1),
            ),
            ColumnWidthMode::Fixed => measure_rows_height_with_col_width_mode(
                &rows,
                &self.state,
                MAX_POPUP_ROWS,
-                rows_width.saturating_add(1),
+                effective_rows_width.saturating_add(1),
                ColumnWidthMode::Fixed,
            ),
        };

-        // Subtract 4 for the padding on the left and right of the header.
-        let mut height = self.header.desired_height(width.saturating_sub(4));
+        let mut height = self.header.desired_height(inner_width);
        height = height.saturating_add(rows_height + 3);
        if self.is_searchable {
            height = height.saturating_add(1);
        }
+
+        // Side content: when the terminal is wide enough the panel sits beside
+        // the list and shares vertical space; otherwise it stacks below.
+        if self.side_layout_width(inner_width).is_some() {
+            // Side-by-side — side content shares list rows vertically so it
+            // doesn't add to total height.
+        } else {
+            let side_h = self.stacked_side_content().desired_height(inner_width);
+            if side_h > 0 {
+                height = height.saturating_add(1 + side_h);
+            }
+        }
+
        if let Some(note) = &self.footer_note {
            let note_width = width.saturating_sub(2);
            let note_lines = wrap_styled_line(note, note_width);
@@ -538,41 +760,60 @@ impl Renderable for ListSelectionView {
        // Paint the shared menu surface and then layout inside the returned inset.
        let content_area = render_menu_surface(outer_content_area, buf);

-        let header_height = self
-            .header
-            // Subtract 4 for the padding on the left and right of the header.
-            .desired_height(outer_content_area.width.saturating_sub(4));
+        let inner_width = popup_content_width(outer_content_area.width);
+        let side_w = self.side_layout_width(inner_width);
+
+        // When side-by-side is active, shrink the list to make room.
+        let full_rows_width = Self::rows_width(outer_content_area.width);
+        let effective_rows_width = if let Some(sw) = side_w {
+            full_rows_width.saturating_sub(SIDE_CONTENT_GAP + sw)
+        } else {
+            full_rows_width
+        };
+
+        let header_height = self.header.desired_height(inner_width);
        let rows = self.build_rows();
-        let rows_width = Self::rows_width(outer_content_area.width);
        let rows_height = match self.col_width_mode {
            ColumnWidthMode::AutoVisible => measure_rows_height(
                &rows,
                &self.state,
                MAX_POPUP_ROWS,
-                rows_width.saturating_add(1),
+                effective_rows_width.saturating_add(1),
            ),
            ColumnWidthMode::AutoAllRows => measure_rows_height_stable_col_widths(
                &rows,
                &self.state,
                MAX_POPUP_ROWS,
-                rows_width.saturating_add(1),
+                effective_rows_width.saturating_add(1),
            ),
            ColumnWidthMode::Fixed => measure_rows_height_with_col_width_mode(
                &rows,
                &self.state,
                MAX_POPUP_ROWS,
-                rows_width.saturating_add(1),
+                effective_rows_width.saturating_add(1),
                ColumnWidthMode::Fixed,
            ),
        };
-        let [header_area, _, search_area, list_area] = Layout::vertical([
+
+        // Stacked (fallback) side content height — only used when not side-by-side.
+        let stacked_side_h = if side_w.is_none() {
+            self.stacked_side_content().desired_height(inner_width)
+        } else {
+            0
+        };
+        let stacked_gap = if stacked_side_h > 0 { 1 } else { 0 };
+
+        let [header_area, _, search_area, list_area, _, stacked_side_area] = Layout::vertical([
            Constraint::Max(header_height),
            Constraint::Max(1),
            Constraint::Length(if self.is_searchable { 1 } else { 0 }),
            Constraint::Length(rows_height),
+            Constraint::Length(stacked_gap),
+            Constraint::Length(stacked_side_h),
        ])
        .areas(content_area);

+        // -- Header --
        if header_area.height < header_height {
            let [header_area, elision_area] =
                Layout::vertical([Constraint::Fill(1), Constraint::Length(1)]).areas(header_area);
@@ -585,6 +826,7 @@ impl Renderable for ListSelectionView {
            self.header.render(header_area, buf);
        }

+        // -- Search bar --
        if self.is_searchable {
            Line::from(self.search_query.clone()).render(search_area, buf);
            let query_span: Span<'static> = if self.search_query.is_empty() {
@@ -598,11 +840,12 @@ impl Renderable for ListSelectionView {
            Line::from(query_span).render(search_area, buf);
        }

+        // -- List rows --
        if list_area.height > 0 {
            let render_area = Rect {
                x: list_area.x.saturating_sub(2),
                y: list_area.y,
-                width: rows_width.max(1),
+                width: effective_rows_width.max(1),
                height: list_area.height,
            };
            match self.col_width_mode {
@@ -634,6 +877,53 @@ impl Renderable for ListSelectionView {
            };
        }

+        // -- Side content (preview panel) --
+        if let Some(sw) = side_w {
+            // Side-by-side: render to the right half of the popup content
+            // area so preview content can center vertically in that panel.
+            let side_x = content_area.x + content_area.width - sw;
+            let side_area = Rect::new(side_x, content_area.y, sw, content_area.height);
+
+            // Clear the menu-surface background behind the side panel so the
+            // preview appears on the terminal's own background.
+            let clear_x = side_x.saturating_sub(SIDE_CONTENT_GAP);
+            let clear_w = outer_content_area
+                .x
+                .saturating_add(outer_content_area.width)
+                .saturating_sub(clear_x);
+            Self::clear_to_terminal_bg(
+                buf,
+                Rect::new(
+                    clear_x,
+                    outer_content_area.y,
+                    clear_w,
+                    outer_content_area.height,
+                ),
+            );
+            self.side_content.render(side_area, buf);
+            Self::force_bg_to_terminal_bg(
+                buf,
+                Rect::new(
+                    clear_x,
+                    outer_content_area.y,
+                    clear_w,
+                    outer_content_area.height,
+                ),
+            );
+        } else if stacked_side_area.height > 0 {
+            // Stacked fallback: render below the list (same as old footer_content).
+            let clear_height = (outer_content_area.y + outer_content_area.height)
+                .saturating_sub(stacked_side_area.y);
+            let clear_area = Rect::new(
+                outer_content_area.x,
+                stacked_side_area.y,
+                outer_content_area.width,
+                clear_height,
+            );
+            Self::clear_to_terminal_bg(buf, clear_area);
+            self.stacked_side_content().render(stacked_side_area, buf);
+        }
+
        if footer_area.height > 0 {
            let [note_area, hint_area] = Layout::vertical([
                Constraint::Length(note_height),
@@ -683,9 +973,33 @@ mod tests {
    use crossterm::event::KeyCode;
    use insta::assert_snapshot;
    use pretty_assertions::assert_eq;
+    use ratatui::buffer::Buffer;
    use ratatui::layout::Rect;
+    use ratatui::style::Color;
+    use ratatui::style::Style;
    use tokio::sync::mpsc::unbounded_channel;

+    struct MarkerRenderable {
+        marker: &'static str,
+        height: u16,
+    }
+
+    impl Renderable for MarkerRenderable {
+        fn render(&self, area: Rect, buf: &mut Buffer) {
+            for y in area.y..area.y.saturating_add(area.height) {
+                for x in area.x..area.x.saturating_add(area.width) {
+                    if x < buf.area().width && y < buf.area().height {
+                        buf[(x, y)].set_symbol(self.marker);
+                    }
+                }
+            }
+        }
+
+        fn desired_height(&self, _width: u16) -> u16 {
+            self.height
+        }
+    }
+
    fn make_selection_view(subtitle: Option<&str>) -> ListSelectionView {
        let (tx_raw, _rx) = unbounded_channel::<AppEvent>();
        let tx = AppEventSender::new(tx_raw);
@@ -722,7 +1036,10 @@ mod tests {
    }

    fn render_lines_with_width(view: &ListSelectionView, width: u16) -> String {
-        let height = view.desired_height(width);
+        render_lines_in_area(view, width, view.desired_height(width))
+    }
+
+    fn render_lines_in_area(view: &ListSelectionView, width: u16, height: u16) -> String {
        let area = Rect::new(0, 0, width, height);
        let mut buf = Buffer::empty(area);
        view.render(area, &mut buf);
@@ -808,6 +1125,20 @@ mod tests {
        assert_snapshot!("list_selection_spacing_with_subtitle", render_lines(&view));
    }

+    #[test]
+    fn theme_picker_subtitle_uses_fallback_text_in_94x35_terminal() {
+        let (tx_raw, _rx) = unbounded_channel::<AppEvent>();
+        let tx = AppEventSender::new(tx_raw);
+        let home = dirs::home_dir().expect("home directory should be available");
+        let codex_home = home.join(".codex");
+        let params =
+            crate::theme_picker::build_theme_picker_params(None, Some(&codex_home), Some(94));
+        let view = ListSelectionView::new(params, tx);
+
+        let rendered = render_lines_in_area(&view, 94, 35);
+        assert!(rendered.contains("Move up/down to live preview themes"));
+    }
+
    #[test]
    fn snapshot_footer_note_wraps() {
        let (tx_raw, _rx) = unbounded_channel::<AppEvent>();
@@ -871,6 +1202,66 @@ mod tests {
        );
    }

+    #[test]
+    fn enter_with_no_matches_triggers_cancel_callback() {
+        let (tx_raw, mut rx) = unbounded_channel::<AppEvent>();
+        let tx = AppEventSender::new(tx_raw);
+        let mut view = ListSelectionView::new(
+            SelectionViewParams {
+                items: vec![SelectionItem {
+                    name: "Read Only".to_string(),
+                    dismiss_on_select: true,
+                    ..Default::default()
+                }],
+                is_searchable: true,
+                on_cancel: Some(Box::new(|tx: &_| {
+                    tx.send(AppEvent::OpenApprovalsPopup);
+                })),
+                ..Default::default()
+            },
+            tx,
+        );
+        view.set_search_query("no-matches".to_string());
+
+        view.handle_key_event(KeyEvent::from(KeyCode::Enter));
+
+        assert!(view.is_complete());
+        match rx.try_recv() {
+            Ok(AppEvent::OpenApprovalsPopup) => {}
+            Ok(other) => panic!("expected OpenApprovalsPopup cancel event, got {other:?}"),
+            Err(err) => panic!("expected cancel callback event, got {err}"),
+        }
+    }
+
+    #[test]
+    fn move_down_without_selection_change_does_not_fire_callback() {
+        let (tx_raw, mut rx) = unbounded_channel::<AppEvent>();
+        let tx = AppEventSender::new(tx_raw);
+        let mut view = ListSelectionView::new(
+            SelectionViewParams {
+                items: vec![SelectionItem {
+                    name: "Only choice".to_string(),
+                    dismiss_on_select: true,
+                    ..Default::default()
+                }],
+                on_selection_changed: Some(Box::new(|_idx, tx: &_| {
+                    tx.send(AppEvent::OpenApprovalsPopup);
+                })),
+                ..Default::default()
+            },
+            tx,
+        );
+
+        while rx.try_recv().is_ok() {}
+
+        view.handle_key_event(KeyEvent::from(KeyCode::Down));
+
+        assert!(
+            rx.try_recv().is_err(),
+            "moving down in a single-item list should not fire on_selection_changed",
+        );
+    }
+
    #[test]
    fn wraps_long_option_without_overflowing_columns() {
        let (tx_raw, _rx) = unbounded_channel::<AppEvent>();
@@ -1159,4 +1550,194 @@ mod tests {
            "fixed description column changed across scroll:\nbefore:\n{before_scroll}\nafter:\n{after_scroll}"
        );
    }
+
+    #[test]
+    fn side_layout_width_half_uses_exact_split() {
+        let (tx_raw, _rx) = unbounded_channel::<AppEvent>();
+        let tx = AppEventSender::new(tx_raw);
+        let view = ListSelectionView::new(
+            SelectionViewParams {
+                items: vec![SelectionItem {
+                    name: "Item 1".to_string(),
+                    dismiss_on_select: true,
+                    ..Default::default()
+                }],
+                side_content: Box::new(MarkerRenderable {
+                    marker: "W",
+                    height: 1,
+                }),
+                side_content_width: SideContentWidth::Half,
+                side_content_min_width: 10,
+                ..Default::default()
+            },
+            tx,
+        );
+
+        let content_width: u16 = 120;
+        let expected = content_width.saturating_sub(SIDE_CONTENT_GAP) / 2;
+        assert_eq!(view.side_layout_width(content_width), Some(expected));
+    }
+
+    #[test]
+    fn side_layout_width_half_falls_back_when_list_would_be_too_narrow() {
+        let (tx_raw, _rx) = unbounded_channel::<AppEvent>();
+        let tx = AppEventSender::new(tx_raw);
+        let view = ListSelectionView::new(
+            SelectionViewParams {
+                items: vec![SelectionItem {
+                    name: "Item 1".to_string(),
+                    dismiss_on_select: true,
+                    ..Default::default()
+                }],
+                side_content: Box::new(MarkerRenderable {
+                    marker: "W",
+                    height: 1,
+                }),
+                side_content_width: SideContentWidth::Half,
+                side_content_min_width: 50,
+                ..Default::default()
+            },
+            tx,
+        );
+
+        assert_eq!(view.side_layout_width(80), None);
+    }
+
+    #[test]
+    fn stacked_side_content_is_used_when_side_by_side_does_not_fit() {
+        let (tx_raw, _rx) = unbounded_channel::<AppEvent>();
+        let tx = AppEventSender::new(tx_raw);
+        let view = ListSelectionView::new(
+            SelectionViewParams {
+                title: Some("Debug".to_string()),
+                items: vec![SelectionItem {
+                    name: "Item 1".to_string(),
+                    dismiss_on_select: true,
+                    ..Default::default()
+                }],
+                side_content: Box::new(MarkerRenderable {
+                    marker: "W",
+                    height: 1,
+                }),
+                stacked_side_content: Some(Box::new(MarkerRenderable {
+                    marker: "N",
+                    height: 1,
+                })),
+                side_content_width: SideContentWidth::Half,
+                side_content_min_width: 60,
+                ..Default::default()
+            },
+            tx,
+        );
+
+        let rendered = render_lines_with_width(&view, 70);
+        assert!(
+            rendered.contains('N'),
+            "expected stacked marker to be rendered:\n{rendered}"
+        );
+        assert!(
+            !rendered.contains('W'),
+            "wide marker should not render in stacked mode:\n{rendered}"
+        );
+    }
+
+    #[test]
+    fn side_content_clearing_resets_symbols_and_style() {
+        let (tx_raw, _rx) = unbounded_channel::<AppEvent>();
+        let tx = AppEventSender::new(tx_raw);
+        let view = ListSelectionView::new(
+            SelectionViewParams {
+                title: Some("Debug".to_string()),
+                items: vec![SelectionItem {
+                    name: "Item 1".to_string(),
+                    dismiss_on_select: true,
+                    ..Default::default()
+                }],
+                side_content: Box::new(MarkerRenderable {
+                    marker: "W",
+                    height: 1,
+                }),
+                side_content_width: SideContentWidth::Half,
+                side_content_min_width: 10,
+                ..Default::default()
+            },
+            tx,
+        );
+
+        let width = 120;
+        let height = view.desired_height(width);
+        let area = Rect::new(0, 0, width, height);
+        let mut buf = Buffer::empty(area);
+        for y in 0..height {
+            for x in 0..width {
+                buf[(x, y)]
+                    .set_symbol("X")
+                    .set_style(Style::default().bg(Color::Red));
+            }
+        }
+        view.render(area, &mut buf);
+
+        let cell = &buf[(width - 1, 0)];
+        assert_eq!(cell.symbol(), " ");
+        let style = cell.style();
+        assert_eq!(style.fg, Some(Color::Reset));
+        assert_eq!(style.bg, Some(Color::Reset));
+        assert_eq!(style.underline_color, Some(Color::Reset));
+
+        let mut saw_marker = false;
+        for y in 0..height {
+            for x in 0..width {
+                let cell = &buf[(x, y)];
+                if cell.symbol() == "W" {
+                    saw_marker = true;
+                    assert_eq!(cell.style().bg, Some(Color::Reset));
+                }
+            }
+        }
+        assert!(
+            saw_marker,
+            "expected side marker renderable to draw into buffer"
+        );
+    }
+
+    #[test]
+    fn side_content_clearing_handles_non_zero_buffer_origin() {
+        let (tx_raw, _rx) = unbounded_channel::<AppEvent>();
+        let tx = AppEventSender::new(tx_raw);
+        let view = ListSelectionView::new(
+            SelectionViewParams {
+                title: Some("Debug".to_string()),
+                items: vec![SelectionItem {
+                    name: "Item 1".to_string(),
+                    dismiss_on_select: true,
+                    ..Default::default()
+                }],
+                side_content: Box::new(MarkerRenderable {
+                    marker: "W",
+                    height: 1,
+                }),
+                side_content_width: SideContentWidth::Half,
+                side_content_min_width: 10,
+                ..Default::default()
+            },
+            tx,
+        );
+
+        let width = 120;
+        let height = view.desired_height(width);
+        let area = Rect::new(0, 20, width, height);
+        let mut buf = Buffer::empty(area);
+        for y in area.y..area.y + height {
+            for x in area.x..area.x + width {
+                buf[(x, y)]
+                    .set_symbol("X")
+                    .set_style(Style::default().bg(Color::Red));
+            }
+        }
+        view.render(area, &mut buf);
+
+        let cell = &buf[(area.x + width - 1, area.y)];
+        assert_eq!(cell.symbol(), " ");
+        assert_eq!(cell.style().bg, Some(Color::Reset));
+    }
 }
--- a/codex-rs/tui/src/bottom_pane/mod.rs
+++ b/codex-rs/tui/src/bottom_pane/mod.rs
@@ -78,6 +78,9 @@ mod slash_commands;
 pub(crate) use footer::CollaborationModeIndicator;
 pub(crate) use list_selection_view::ColumnWidthMode;
 pub(crate) use list_selection_view::SelectionViewParams;
+pub(crate) use list_selection_view::SideContentWidth;
+pub(crate) use list_selection_view::popup_content_width;
+pub(crate) use list_selection_view::side_by_side_layout_widths;
 mod feedback_view;
 pub(crate) use feedback_view::FeedbackAudience;
 pub(crate) use feedback_view::feedback_disabled_params;
--- a/codex-rs/tui/src/chatwidget.rs
+++ b/codex-rs/tui/src/chatwidget.rs
@@ -3482,6 +3482,9 @@ impl ChatWidget {
            SlashCommand::Statusline => {
                self.open_status_line_setup();
            }
+            SlashCommand::Theme => {
+                self.open_theme_picker();
+            }
            SlashCommand::Ps => {
                self.add_ps_output();
            }
@@ -4431,6 +4434,20 @@ impl ChatWidget {
        self.bottom_pane.show_view(Box::new(view));
    }

+    fn open_theme_picker(&mut self) {
+        let codex_home = codex_core::config::find_codex_home().ok();
+        let terminal_width = self
+            .last_rendered_width
+            .get()
+            .and_then(|width| u16::try_from(width).ok());
+        let params = crate::theme_picker::build_theme_picker_params(
+            self.config.tui_theme.as_deref(),
+            codex_home.as_deref(),
+            terminal_width,
+        );
+        self.bottom_pane.show_selection_view(params);
+    }
+
    /// Parses configured status-line ids into known items and collects unknown ids.
    ///
    /// Unknown ids are deduplicated in insertion order for warning messages.
@@ -6338,6 +6355,11 @@ impl ChatWidget {
        self.config.personality = Some(personality);
    }

+    /// Set the syntax theme override in the widget's config copy.
+    pub(crate) fn set_tui_theme(&mut self, theme: Option<String>) {
+        self.config.tui_theme = theme;
+    }
+
    /// Set the model in the widget's config copy and stored collaboration mode.
    pub(crate) fn set_model(&mut self, model: &str) {
        self.current_collaboration_mode =
--- a/codex-rs/tui/src/chatwidget/snapshots/codex_tuichatwidgettests__exec_approval_modal_exec.snap
+++ b/codex-rs/tui/src/chatwidget/snapshots/codex_tuichatwidgettests__exec_approval_modal_exec.snap
@@ -27,6 +27,9 @@ Buffer {
        x: 73, y: 4, fg: Reset, bg: Reset, underline: Reset, modifier: NONE,
        x: 2, y: 5, fg: Reset, bg: Reset, underline: Reset, modifier: ITALIC,
        x: 7, y: 5, fg: Reset, bg: Reset, underline: Reset, modifier: NONE,
+        x: 4, y: 7, fg: Rgb(137, 180, 250), bg: Reset, underline: Reset, modifier: NONE,
+        x: 8, y: 7, fg: Rgb(205, 214, 244), bg: Reset, underline: Reset, modifier: NONE,
+        x: 20, y: 7, fg: Reset, bg: Reset, underline: Reset, modifier: NONE,
        x: 0, y: 9, fg: Cyan, bg: Reset, underline: Reset, modifier: BOLD,
        x: 21, y: 9, fg: Reset, bg: Reset, underline: Reset, modifier: NONE,
        x: 48, y: 10, fg: Reset, bg: Reset, underline: Reset, modifier: DIM,
--- a/codex-rs/tui/src/diff_render.rs
+++ b/codex-rs/tui/src/diff_render.rs
--- a/codex-rs/tui/src/lib.rs
+++ b/codex-rs/tui/src/lib.rs
@@ -105,6 +105,7 @@ mod streaming;
 mod style;
 mod terminal_palette;
 mod text_formatting;
+mod theme_picker;
 mod tooltips;
 mod tui;
 mod ui_consts;
@@ -545,6 +546,7 @@ async fn run_ratatui_app(
    } else {
        initial_config
    };
+
    let mut missing_session_exit = |id_str: &str, action: &str| {
        error!("Error finding conversation path: {id_str}");
        restore();
@@ -693,7 +695,7 @@ async fn run_ratatui_app(
        None => None,
    };

-    let config = match &session_selection {
+    let mut config = match &session_selection {
        resume_picker::SessionSelection::Resume(_) | resume_picker::SessionSelection::Fork(_) => {
            load_config_or_exit_with_fallback_cwd(
                cli_kv_overrides.clone(),
@@ -705,6 +707,17 @@ async fn run_ratatui_app(
        }
        _ => config,
    };
+
+    // Configure syntax highlighting theme from the final config — onboarding
+    // and resume/fork can both reload config with a different tui_theme, so
+    // this must happen after the last possible reload.
+    if let Some(w) = crate::render::highlight::set_theme_override(
+        config.tui_theme.clone(),
+        find_codex_home().ok(),
+    ) {
+        config.startup_warnings.push(w);
+    }
+
    set_default_client_residency_requirement(config.enforce_residency.value());
    let active_profile = config.active_profile.clone();
    let should_show_trust_screen = should_show_trust_screen(&config);
@@ -1186,6 +1199,50 @@ trust_level = "untrusted"
        Ok(())
    }

+    /// Regression: theme must be configured from the *final* config.
+    ///
+    /// `run_ratatui_app` can reload config during onboarding and again
+    /// during session resume/fork.  The syntax theme override (stored in
+    /// a `OnceLock`) must use the final config's `tui_theme`, not the
+    /// initial one — otherwise users resuming a thread in a project with
+    /// a different theme get the wrong highlighting.
+    ///
+    /// We verify the invariant indirectly: `validate_theme_name` (the
+    /// pure validation core of `set_theme_override`) must be called with
+    /// the *final* config's theme, and its warning must land in the
+    /// final config's `startup_warnings`.
+    #[tokio::test]
+    async fn theme_warning_uses_final_config() -> std::io::Result<()> {
+        use crate::render::highlight::validate_theme_name;
+
+        let temp_dir = TempDir::new()?;
+
+        // initial_config has a valid theme — no warning.
+        let initial_config = build_config(&temp_dir).await?;
+        assert!(initial_config.tui_theme.is_none());
+
+        // Simulate resume/fork reload: the final config has an invalid theme.
+        let mut config = build_config(&temp_dir).await?;
+        config.tui_theme = Some("bogus-theme".into());
+
+        // Theme override must use the final config (not initial_config).
+        // This mirrors the real call site in run_ratatui_app.
+        if let Some(w) = validate_theme_name(config.tui_theme.as_deref(), Some(temp_dir.path())) {
+            config.startup_warnings.push(w);
+        }
+
+        assert_eq!(
+            config.startup_warnings.len(),
+            1,
+            "warning from final config's invalid theme should be present"
+        );
+        assert!(
+            config.startup_warnings[0].contains("bogus-theme"),
+            "warning should reference the final config's theme name"
+        );
+        Ok(())
+    }
+
    #[tokio::test]
    async fn read_session_cwd_falls_back_to_session_meta() -> std::io::Result<()> {
        let temp_dir = TempDir::new()?;
--- a/codex-rs/tui/src/markdown_render.rs
+++ b/codex-rs/tui/src/markdown_render.rs
@@ -1,3 +1,4 @@
+use crate::render::highlight::highlight_code_to_lines;
 use crate::render::line_utils::line_to_static;
 use crate::wrapping::RtOptions;
 use crate::wrapping::word_wrap_line;
@@ -99,6 +100,8 @@ where
    pending_marker_line: bool,
    in_paragraph: bool,
    in_code_block: bool,
+    code_block_lang: Option<String>,
+    code_block_buffer: String,
    wrap_width: Option<usize>,
    current_line_content: Option<Line<'static>>,
    current_initial_indent: Vec<Span<'static>>,
@@ -124,6 +127,8 @@ where
            pending_marker_line: false,
            in_paragraph: false,
            in_code_block: false,
+            code_block_lang: None,
+            code_block_buffer: String::new(),
            wrap_width,
            current_line_content: None,
            current_initial_indent: Vec::new(),
@@ -278,6 +283,16 @@ where
            self.push_line(Line::default());
        }
        self.pending_marker_line = false;
+
+        // When inside a fenced code block with a known language, accumulate
+        // text into the buffer for batch highlighting in end_codeblock().
+        // Append verbatim — pulldown-cmark text events already contain the
+        // original line breaks, so inserting separators would double them.
+        if self.in_code_block && self.code_block_lang.is_some() {
+            self.code_block_buffer.push_str(&text);
+            return;
+        }
+
        if self.in_code_block && !self.needs_newline {
            let has_content = self
                .current_line_content
@@ -394,12 +409,25 @@ where
        self.needs_newline = false;
    }

-    fn start_codeblock(&mut self, _lang: Option<String>, indent: Option<Span<'static>>) {
+    fn start_codeblock(&mut self, lang: Option<String>, indent: Option<Span<'static>>) {
        self.flush_current_line();
        if !self.text.lines.is_empty() {
            self.push_blank_line();
        }
        self.in_code_block = true;
+
+        // Extract the language token from the info string.  CommonMark info
+        // strings can contain metadata after the language, separated by commas,
+        // spaces, or other delimiters (e.g. "rust,no_run", "rust title=demo").
+        // Take only the first token so the syntax lookup succeeds.
+        let lang = lang
+            .as_deref()
+            .and_then(|s| s.split([',', ' ', '\t']).next())
+            .filter(|s| !s.is_empty())
+            .map(std::string::ToString::to_string);
+        self.code_block_lang = lang;
+        self.code_block_buffer.clear();
+
        self.indent_stack.push(IndentContext::new(
            vec![indent.unwrap_or_default()],
            None,
@@ -409,6 +437,20 @@ where
    }

    fn end_codeblock(&mut self) {
+        // If we buffered code for a known language, syntax-highlight it now.
+        if let Some(lang) = self.code_block_lang.take() {
+            let code = std::mem::take(&mut self.code_block_buffer);
+            if !code.is_empty() {
+                let highlighted = highlight_code_to_lines(&code, &lang);
+                for hl_line in highlighted {
+                    self.push_line(Line::default());
+                    for span in hl_line.spans {
+                        self.push_span(span);
+                    }
+                }
+            }
+        }
+
        self.needs_newline = true;
        self.in_code_block = false;
        self.indent_stack.pop();
@@ -675,4 +717,39 @@ mod tests {
            vec!["fn main() { println!(\"hi from a long line\"); }".to_string(),]
        );
    }
+
+    #[test]
+    fn fenced_code_info_string_with_metadata_highlights() {
+        // CommonMark info strings like "rust,no_run" or "rust title=demo"
+        // contain metadata after the language token.  The language must be
+        // extracted (first word / comma-separated token) so highlighting works.
+        for info in &["rust,no_run", "rust no_run", "rust title=\"demo\""] {
+            let markdown = format!("```{info}\nfn main() {{}}\n```\n");
+            let rendered = render_markdown_text(&markdown);
+            let has_rgb = rendered.lines.iter().any(|line| {
+                line.spans
+                    .iter()
+                    .any(|s| matches!(s.style.fg, Some(ratatui::style::Color::Rgb(..))))
+            });
+            assert!(
+                has_rgb,
+                "info string \"{info}\" should still produce syntax highlighting"
+            );
+        }
+    }
+
+    #[test]
+    fn crlf_code_block_no_extra_blank_lines() {
+        // pulldown-cmark can split CRLF code blocks into multiple Text events.
+        // The buffer must concatenate them verbatim — no inserted separators.
+        let markdown = "```rust\r\nfn main() {}\r\n    line2\r\n```\r\n";
+        let rendered = render_markdown_text(markdown);
+        let lines = lines_to_strings(&rendered);
+        // Should be exactly two code lines; no spurious blank line between them.
+        assert_eq!(
+            lines,
+            vec!["fn main() {}".to_string(), "    line2".to_string()],
+            "CRLF code block should not produce extra blank lines: {lines:?}"
+        );
+    }
 }
--- a/codex-rs/tui/src/markdown_render_tests.rs
+++ b/codex-rs/tui/src/markdown_render_tests.rs
@@ -652,10 +652,83 @@ fn link() {
 }

 #[test]
-fn code_block_unhighlighted() {
+fn code_block_known_lang_has_syntax_colors() {
    let text = render_markdown_text("```rust\nfn main() {}\n```\n");
-    let expected = Text::from_iter([Line::from_iter(["", "fn main() {}"])]);
-    assert_eq!(text, expected);
+    let content: Vec<String> = text
+        .lines
+        .iter()
+        .map(|l| {
+            l.spans
+                .iter()
+                .map(|s| s.content.clone())
+                .collect::<String>()
+        })
+        .collect();
+    // Content should be preserved; ignore trailing empty line from highlighting.
+    let content: Vec<&str> = content
+        .iter()
+        .map(std::string::String::as_str)
+        .filter(|s| !s.is_empty())
+        .collect();
+    assert_eq!(content, vec!["fn main() {}"]);
+
+    // At least one span should have non-default style (syntax highlighting).
+    let has_colored_span = text
+        .lines
+        .iter()
+        .flat_map(|l| l.spans.iter())
+        .any(|sp| sp.style.fg.is_some());
+    assert!(has_colored_span, "expected syntax-highlighted spans with color");
+}
+
+#[test]
+fn code_block_unknown_lang_plain() {
+    let text = render_markdown_text("```xyzlang\nhello world\n```\n");
+    let content: Vec<String> = text
+        .lines
+        .iter()
+        .map(|l| {
+            l.spans
+                .iter()
+                .map(|s| s.content.clone())
+                .collect::<String>()
+        })
+        .collect();
+    let content: Vec<&str> = content
+        .iter()
+        .map(std::string::String::as_str)
+        .filter(|s| !s.is_empty())
+        .collect();
+    assert_eq!(content, vec!["hello world"]);
+
+    // No syntax coloring for unknown language — all spans have default style.
+    let has_colored_span = text
+        .lines
+        .iter()
+        .flat_map(|l| l.spans.iter())
+        .any(|sp| sp.style.fg.is_some());
+    assert!(!has_colored_span, "expected no syntax coloring for unknown lang");
+}
+
+#[test]
+fn code_block_no_lang_plain() {
+    let text = render_markdown_text("```\nno lang specified\n```\n");
+    let content: Vec<String> = text
+        .lines
+        .iter()
+        .map(|l| {
+            l.spans
+                .iter()
+                .map(|s| s.content.clone())
+                .collect::<String>()
+        })
+        .collect();
+    let content: Vec<&str> = content
+        .iter()
+        .map(std::string::String::as_str)
+        .filter(|s| !s.is_empty())
+        .collect();
+    assert_eq!(content, vec!["no lang specified"]);
 }

 #[test]
@@ -721,16 +794,25 @@ Here is a code block that shows another fenced block:
                .collect::<String>()
        })
        .collect();
+    // Filter empty trailing lines for stability; the code block may or may
+    // not emit a trailing blank depending on the highlighting path.
+    let trimmed: Vec<&str> = {
+        let mut v: Vec<&str> = lines.iter().map(std::string::String::as_str).collect();
+        while v.last() == Some(&"") {
+            v.pop();
+        }
+        v
+    };
    assert_eq!(
-        lines,
+        trimmed,
        vec![
-            "Here is a code block that shows another fenced block:".to_string(),
-            String::new(),
-            "```md".to_string(),
-            "# Inside fence".to_string(),
-            "- bullet".to_string(),
-            "- `inline code`".to_string(),
-            "```".to_string(),
+            "Here is a code block that shows another fenced block:",
+            "",
+            "```md",
+            "# Inside fence",
+            "- bullet",
+            "- `inline code`",
+            "```",
        ]
    );
 }
@@ -993,3 +1075,36 @@ fn nested_item_continuation_paragraph_is_indented() {
    ]);
    assert_eq!(text, expected);
 }
+
+#[test]
+fn code_block_preserves_trailing_blank_lines() {
+    // A fenced code block with an intentional trailing blank line must keep it.
+    let md = "```rust\nfn main() {}\n\n```\n";
+    let text = render_markdown_text(md);
+    let content: Vec<String> = text
+        .lines
+        .iter()
+        .map(|l| {
+            l.spans
+                .iter()
+                .map(|s| s.content.clone())
+                .collect::<String>()
+        })
+        .collect();
+    // Should have: "fn main() {}" then "" (the blank line).
+    // Filter only to content lines (skip leading/trailing empty from rendering).
+    assert!(
+        content.iter().any(|c| c == "fn main() {}"),
+        "expected code line, got {content:?}"
+    );
+    // The trailing blank line inside the fence should be preserved.
+    let code_start = content.iter().position(|c| c == "fn main() {}").unwrap();
+    assert!(
+        content.len() > code_start + 1,
+        "expected a line after 'fn main() {{}}' but content ends: {content:?}"
+    );
+    assert_eq!(
+        content[code_start + 1], "",
+        "trailing blank line inside code fence was lost: {content:?}"
+    );
+}
--- a/codex-rs/tui/src/render/highlight.rs
+++ b/codex-rs/tui/src/render/highlight.rs
--- a/codex-rs/tui/src/slash_command.rs
+++ b/codex-rs/tui/src/slash_command.rs
@@ -37,6 +37,7 @@ pub enum SlashCommand {
    Status,
    DebugConfig,
    Statusline,
+    Theme,
    Mcp,
    Apps,
    Logout,
@@ -75,6 +76,7 @@ impl SlashCommand {
            SlashCommand::Status => "show current session configuration and token usage",
            SlashCommand::DebugConfig => "show config layers and requirement sources for debugging",
            SlashCommand::Statusline => "configure which items appear in the status line",
+            SlashCommand::Theme => "choose a syntax highlighting theme",
            SlashCommand::Ps => "list background terminals",
            SlashCommand::Clean => "stop all background terminals",
            SlashCommand::MemoryDrop => "DO NOT USE",
@@ -155,6 +157,7 @@ impl SlashCommand {
            SlashCommand::Collab => true,
            SlashCommand::Agent => true,
            SlashCommand::Statusline => false,
+            SlashCommand::Theme => false,
        }
    }

--- a/codex-rs/tui/src/snapshots/codex_tui__diff_rendertestsdiff_gallery_120x40.snap
+++ b/codex-rs/tui/src/snapshots/codex_tui__diff_rendertestsdiff_gallery_120x40.snap
@@ -0,0 +1,44 @@
+---
+source: tui/src/diff_render.rs
+expression: terminal.backend()
+---
+"• Edited 6 files (+9 -9)                                                                                                "
+"  └ assets/banner.txt (+3 -0)                                                                                           "
+"    1 +HEADER	VALUE                                                                                                     "
+"    2 +rocket	🚀                                                                                                        " Hidden by multi-width symbols: [(15, " ")]
+"    3 +city	東京                                                                                                        " Hidden by multi-width symbols: [(13, " "), (15, " ")]
+"                                                                                                                        "
+"  └ examples/new_sample.rs (+3 -0)                                                                                      "
+"    1 +pub fn greet(name: &str) {                                                                                       "
+"    2 +    println!("Hello, {name}!");                                                                                  "
+"    3 +}                                                                                                                "
+"                                                                                                                        "
+"  └ legacy/old_script.py (+0 -3)                                                                                        "
+"    1 -def legacy(x):                                                                                                   "
+"    2 -    return x + 1                                                                                                 "
+"    3 -print(legacy(3))                                                                                                 "
+"                                                                                                                        "
+"  └ scripts/calc.txt → scripts/calc.py (+1 -1)                                                                          "
+"    1  def add(a, b):                                                                                                   "
+"    2 -	return a + b                                                                                                    "
+"    2 +	return a + b + 42                                                                                               "
+"    3                                                                                                                   "
+"    4  print(add(1, 2))                                                                                                 "
+"                                                                                                                        "
+"  └ src/lib.rs (+2 -2)                                                                                                  "
+"    1  fn greet(name: &str) {                                                                                           "
+"    2 -    println!("hello");                                                                                           "
+"    3 -    println!("bye");                                                                                             "
+"    2 +    println!("hello {name}");                                                                                    "
+"    3 +    println!("emoji: 🚀✨ and CJK: 你好世界");                                                                   " Hidden by multi-width symbols: [(29, " "), (31, " "), (43, " "), (45, " "), (47, " "), (49, " ")]
+"    4  }                                                                                                                "
+"                                                                                                                        "
+"  └ tmp/obsolete.log (+0 -3)                                                                                            "
+"    1 -old line 1                                                                                                       "
+"    2 -old line 2                                                                                                       "
+"    3 -old line 3                                                                                                       "
+"                                                                                                                        "
+"                                                                                                                        "
+"                                                                                                                        "
+"                                                                                                                        "
+"                                                                                                                        "
--- a/codex-rs/tui/src/snapshots/codex_tui__diff_rendertestsdiff_gallery_80x24.snap
+++ b/codex-rs/tui/src/snapshots/codex_tui__diff_rendertestsdiff_gallery_80x24.snap
@@ -0,0 +1,28 @@
+---
+source: tui/src/diff_render.rs
+expression: terminal.backend()
+---
+"• Edited 6 files (+9 -9)                                                        "
+"  └ assets/banner.txt (+3 -0)                                                   "
+"    1 +HEADER	VALUE                                                             "
+"    2 +rocket	🚀                                                                " Hidden by multi-width symbols: [(15, " ")]
+"    3 +city	東京                                                                " Hidden by multi-width symbols: [(13, " "), (15, " ")]
+"                                                                                "
+"  └ examples/new_sample.rs (+3 -0)                                              "
+"    1 +pub fn greet(name: &str) {                                               "
+"    2 +    println!("Hello, {name}!");                                          "
+"    3 +}                                                                        "
+"                                                                                "
+"  └ legacy/old_script.py (+0 -3)                                                "
+"    1 -def legacy(x):                                                           "
+"    2 -    return x + 1                                                         "
+"    3 -print(legacy(3))                                                         "
+"                                                                                "
+"  └ scripts/calc.txt → scripts/calc.py (+1 -1)                                  "
+"    1  def add(a, b):                                                           "
+"    2 -	return a + b                                                            "
+"    2 +	return a + b + 42                                                       "
+"    3                                                                           "
+"    4  print(add(1, 2))                                                         "
+"                                                                                "
+"  └ src/lib.rs (+2 -2)                                                          "
--- a/codex-rs/tui/src/snapshots/codex_tui__diff_rendertestsdiff_gallery_94x35.snap
+++ b/codex-rs/tui/src/snapshots/codex_tui__diff_rendertestsdiff_gallery_94x35.snap
@@ -0,0 +1,39 @@
+---
+source: tui/src/diff_render.rs
+expression: terminal.backend()
+---
+"• Edited 6 files (+9 -9)                                                                      "
+"  └ assets/banner.txt (+3 -0)                                                                 "
+"    1 +HEADER	VALUE                                                                           "
+"    2 +rocket	🚀                                                                              " Hidden by multi-width symbols: [(15, " ")]
+"    3 +city	東京                                                                              " Hidden by multi-width symbols: [(13, " "), (15, " ")]
+"                                                                                              "
+"  └ examples/new_sample.rs (+3 -0)                                                            "
+"    1 +pub fn greet(name: &str) {                                                             "
+"    2 +    println!("Hello, {name}!");                                                        "
+"    3 +}                                                                                      "
+"                                                                                              "
+"  └ legacy/old_script.py (+0 -3)                                                              "
+"    1 -def legacy(x):                                                                         "
+"    2 -    return x + 1                                                                       "
+"    3 -print(legacy(3))                                                                       "
+"                                                                                              "
+"  └ scripts/calc.txt → scripts/calc.py (+1 -1)                                                "
+"    1  def add(a, b):                                                                         "
+"    2 -	return a + b                                                                          "
+"    2 +	return a + b + 42                                                                     "
+"    3                                                                                         "
+"    4  print(add(1, 2))                                                                       "
+"                                                                                              "
+"  └ src/lib.rs (+2 -2)                                                                        "
+"    1  fn greet(name: &str) {                                                                 "
+"    2 -    println!("hello");                                                                 "
+"    3 -    println!("bye");                                                                   "
+"    2 +    println!("hello {name}");                                                          "
+"    3 +    println!("emoji: 🚀✨ and CJK: 你好世界");                                         " Hidden by multi-width symbols: [(29, " "), (31, " "), (43, " "), (45, " "), (47, " "), (49, " ")]
+"    4  }                                                                                      "
+"                                                                                              "
+"  └ tmp/obsolete.log (+0 -3)                                                                  "
+"    1 -old line 1                                                                             "
+"    2 -old line 2                                                                             "
+"    3 -old line 3                                                                             "
--- a/codex-rs/tui/src/snapshots/codex_tui__diff_rendertestssyntax_highlighted_insert_wraps.snap
+++ b/codex-rs/tui/src/snapshots/codex_tui__diff_rendertestssyntax_highlighted_insert_wraps.snap
@@ -0,0 +1,14 @@
+---
+source: tui/src/diff_render.rs
+expression: terminal.backend()
+---
+"1 +fn very_long_function_name(arg_one: String, arg_two: String, arg_three: Strin          "
+"   g, arg_four: String) -> Result<String, Box<dyn std::error::Error>> { Ok(arg_o          "
+"   ne) }                                                                                  "
+"                                                                                          "
+"                                                                                          "
+"                                                                                          "
+"                                                                                          "
+"                                                                                          "
+"                                                                                          "
+"                                                                                          "
--- a/codex-rs/tui/src/snapshots/codex_tui__diff_rendertestssyntax_highlighted_insert_wraps_text.snap
+++ b/codex-rs/tui/src/snapshots/codex_tui__diff_rendertestssyntax_highlighted_insert_wraps_text.snap
@@ -0,0 +1,7 @@
+---
+source: tui/src/diff_render.rs
+expression: text
+---
+1 +fn very_long_function_name(arg_one: String, arg_two: String, arg_three: Strin
+   g, arg_four: String) -> Result<String, Box<dyn std::error::Error>> { Ok(arg_o
+   ne) }
--- a/codex-rs/tui/src/theme_picker.rs
+++ b/codex-rs/tui/src/theme_picker.rs
@@ -0,0 +1,620 @@
+//! Builds the `/theme` picker dialog for the TUI.
+//!
+//! The picker lists all bundled themes plus any custom `.tmTheme` files found
+//! under `{CODEX_HOME}/themes/`.  It provides:
+//!
+//! - **Live preview:** the `on_selection_changed` callback swaps the runtime
+//!   syntax theme as the user navigates, giving instant visual feedback in both
+//!   the preview panel and any visible code blocks.
+//! - **Cancel-restore:** on dismiss (Esc / Ctrl+C) the `on_cancel` callback
+//!   restores the theme snapshot taken when the picker opened.
+//! - **Persist on confirm:** the `AppEvent::SyntaxThemeSelected` action persists
+//!   `[tui] theme = "..."` to `config.toml` via `ConfigEditsBuilder`.
+//!
+//! Two preview renderables adapt to terminal width:
+//!
+//! - `ThemePreviewWideRenderable` -- vertically centered, inset by 2 columns,
+//!   shown in the side panel when the terminal is wide enough for side-by-side
+//!   layout (>= 44-column side panel and >= 40-column list).
+//! - `ThemePreviewNarrowRenderable` -- compact 4-line snippet stacked below the
+//!   list when side-by-side does not fit.
+
+use std::path::Path;
+
+use crate::app_event::AppEvent;
+use crate::bottom_pane::SelectionItem;
+use crate::bottom_pane::SelectionViewParams;
+use crate::bottom_pane::SideContentWidth;
+use crate::bottom_pane::popup_consts::standard_popup_hint_line;
+use crate::bottom_pane::popup_content_width;
+use crate::bottom_pane::side_by_side_layout_widths;
+use crate::diff_render::DiffLineType;
+use crate::diff_render::line_number_width;
+use crate::diff_render::push_wrapped_diff_line;
+use crate::diff_render::push_wrapped_diff_line_with_syntax;
+use crate::render::highlight;
+use crate::render::renderable::Renderable;
+use crate::status::format_directory_display;
+use ratatui::buffer::Buffer;
+use ratatui::layout::Rect;
+use ratatui::text::Line;
+use ratatui::widgets::Widget;
+use unicode_width::UnicodeWidthStr;
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+enum PreviewDiffKind {
+    Context,
+    Added,
+    Removed,
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+struct PreviewRow {
+    line_no: usize,
+    kind: PreviewDiffKind,
+    code: &'static str,
+}
+
+/// Compact fallback preview used in stacked (narrow) mode.
+/// Keep exactly one removed and one added line visible at all times.
+const NARROW_PREVIEW_ROWS: [PreviewRow; 4] = [
+    PreviewRow {
+        line_no: 12,
+        kind: PreviewDiffKind::Context,
+        code: "fn greet(name: &str) -> String {",
+    },
+    PreviewRow {
+        line_no: 13,
+        kind: PreviewDiffKind::Removed,
+        code: "    format!(\"Hello, {}!\", name)",
+    },
+    PreviewRow {
+        line_no: 13,
+        kind: PreviewDiffKind::Added,
+        code: "    format!(\"Hello, {name}!\")",
+    },
+    PreviewRow {
+        line_no: 14,
+        kind: PreviewDiffKind::Context,
+        code: "}",
+    },
+];
+
+/// Wider diff preview used in side-by-side mode.
+/// This sample intentionally mixes context, additions, and removals.
+const WIDE_PREVIEW_ROWS: [PreviewRow; 8] = [
+    PreviewRow {
+        line_no: 31,
+        kind: PreviewDiffKind::Context,
+        code: "fn summarize(users: &[User]) -> String {",
+    },
+    PreviewRow {
+        line_no: 32,
+        kind: PreviewDiffKind::Removed,
+        code: "    let active = users.iter().filter(|u| u.is_active).count();",
+    },
+    PreviewRow {
+        line_no: 32,
+        kind: PreviewDiffKind::Added,
+        code: "    let active = users.iter().filter(|u| u.is_active()).count();",
+    },
+    PreviewRow {
+        line_no: 33,
+        kind: PreviewDiffKind::Context,
+        code: "    let names: Vec<&str> = users.iter().map(User::name).take(3).collect();",
+    },
+    PreviewRow {
+        line_no: 34,
+        kind: PreviewDiffKind::Removed,
+        code: "    format!(\"{} active: {}\", active, names.join(\", \"))",
+    },
+    PreviewRow {
+        line_no: 34,
+        kind: PreviewDiffKind::Added,
+        code: "    format!(\"{active} active users: {}\", names.join(\", \"))",
+    },
+    PreviewRow {
+        line_no: 35,
+        kind: PreviewDiffKind::Added,
+        code: "        .trim()",
+    },
+    PreviewRow {
+        line_no: 36,
+        kind: PreviewDiffKind::Context,
+        code: "}",
+    },
+];
+
+/// Minimum side-panel width for side-by-side theme preview.
+const WIDE_PREVIEW_MIN_WIDTH: u16 = 44;
+
+/// Left inset used for wide preview content.
+const WIDE_PREVIEW_LEFT_INSET: u16 = 2;
+
+/// Minimum frame padding used for vertically centered wide preview.
+const PREVIEW_FRAME_PADDING: u16 = 1;
+
+const PREVIEW_FALLBACK_SUBTITLE: &str = "Move up/down to live preview themes";
+
+/// Side-by-side preview: syntax-highlighted Rust diff snippet, vertically
+/// centered with a 2-column left inset.  Fills the entire side panel height.
+struct ThemePreviewWideRenderable;
+
+/// Stacked preview: compact 4-line Rust diff snippet shown below the list
+/// when the terminal is too narrow for side-by-side layout.
+struct ThemePreviewNarrowRenderable;
+
+fn preview_diff_line_type(kind: PreviewDiffKind) -> DiffLineType {
+    match kind {
+        PreviewDiffKind::Context => DiffLineType::Context,
+        PreviewDiffKind::Added => DiffLineType::Insert,
+        PreviewDiffKind::Removed => DiffLineType::Delete,
+    }
+}
+
+fn centered_offset(available: u16, content: u16, min_frame: u16) -> u16 {
+    let free = available.saturating_sub(content);
+    let frame = if free >= min_frame.saturating_mul(2) {
+        min_frame
+    } else {
+        0
+    };
+    frame + free.saturating_sub(frame.saturating_mul(2)) / 2
+}
+
+fn render_preview(
+    area: Rect,
+    buf: &mut Buffer,
+    preview_rows: &[PreviewRow],
+    center_vertically: bool,
+    left_inset: u16,
+) {
+    if area.height == 0 || area.width == 0 {
+        return;
+    }
+    if preview_rows.is_empty() {
+        return;
+    }
+    let preview_code = preview_rows
+        .iter()
+        .map(|row| row.code)
+        .collect::<Vec<_>>()
+        .join("\n");
+    let syntax_lines = highlight::highlight_code_to_styled_spans(&preview_code, "rust");
+
+    let max_line_no = preview_rows
+        .iter()
+        .map(|row| row.line_no)
+        .max()
+        .unwrap_or(1);
+    let ln_width = line_number_width(max_line_no);
+
+    let content_height = (preview_rows.len() as u16).min(area.height);
+
+    let left_pad = left_inset.min(area.width.saturating_sub(1));
+    let top_pad = if center_vertically {
+        centered_offset(area.height, content_height, PREVIEW_FRAME_PADDING)
+    } else {
+        0
+    };
+
+    let mut y = area.y.saturating_add(top_pad);
+    let render_width = area.width.saturating_sub(left_pad);
+    for (idx, row) in preview_rows.iter().enumerate() {
+        if y >= area.y + area.height {
+            break;
+        }
+        let diff_type = preview_diff_line_type(row.kind);
+        let wrapped = if let Some(syn) = syntax_lines.as_ref().and_then(|sl| sl.get(idx)) {
+            push_wrapped_diff_line_with_syntax(
+                row.line_no,
+                diff_type,
+                row.code,
+                render_width as usize,
+                ln_width,
+                syn,
+            )
+        } else {
+            push_wrapped_diff_line(
+                row.line_no,
+                diff_type,
+                row.code,
+                render_width as usize,
+                ln_width,
+            )
+        };
+        let first_line = wrapped.into_iter().next().unwrap_or_else(|| Line::from(""));
+        first_line.render(
+            Rect::new(area.x.saturating_add(left_pad), y, render_width, 1),
+            buf,
+        );
+        y += 1;
+    }
+}
+
+impl Renderable for ThemePreviewWideRenderable {
+    fn desired_height(&self, _width: u16) -> u16 {
+        u16::MAX
+    }
+
+    fn render(&self, area: Rect, buf: &mut Buffer) {
+        render_preview(area, buf, &WIDE_PREVIEW_ROWS, true, WIDE_PREVIEW_LEFT_INSET);
+    }
+}
+
+impl Renderable for ThemePreviewNarrowRenderable {
+    fn desired_height(&self, _width: u16) -> u16 {
+        NARROW_PREVIEW_ROWS.len() as u16
+    }
+
+    fn render(&self, area: Rect, buf: &mut Buffer) {
+        render_preview(area, buf, &NARROW_PREVIEW_ROWS, false, 0);
+    }
+}
+
+fn subtitle_available_width(terminal_width: Option<u16>) -> usize {
+    let width = terminal_width.unwrap_or(80);
+    let content_width = popup_content_width(width);
+    if let Some((list_width, _side_width)) = side_by_side_layout_widths(
+        content_width,
+        SideContentWidth::Half,
+        WIDE_PREVIEW_MIN_WIDTH,
+    ) {
+        list_width as usize
+    } else {
+        content_width as usize
+    }
+}
+
+fn theme_picker_subtitle(codex_home: Option<&Path>, terminal_width: Option<u16>) -> String {
+    let themes_dir = codex_home.map(|home| home.join("themes"));
+    let themes_dir_display = themes_dir
+        .as_deref()
+        .map(|path| format_directory_display(path, None));
+    let available_width = subtitle_available_width(terminal_width);
+
+    if let Some(path) = themes_dir_display
+        && path.starts_with('~')
+    {
+        let subtitle = format!("Custom .tmTheme files can be added to the {path} directory.");
+        if UnicodeWidthStr::width(subtitle.as_str()) <= available_width {
+            return subtitle;
+        }
+    }
+
+    PREVIEW_FALLBACK_SUBTITLE.to_string()
+}
+
+/// Builds [`SelectionViewParams`] for the `/theme` picker dialog.
+///
+/// Lists all bundled themes plus custom `.tmTheme` files, with live preview
+/// on cursor movement and cancel-restore.
+///
+/// `current_name` should be the value of `Config::tui_theme` (the persisted
+/// preference).  When it names a theme that is currently available the picker
+/// pre-selects it; otherwise the picker falls back to the configured name (or
+/// adaptive default) so opening the picker without a persisted preference still
+/// highlights the most likely intended entry.
+pub(crate) fn build_theme_picker_params(
+    current_name: Option<&str>,
+    codex_home: Option<&Path>,
+    terminal_width: Option<u16>,
+) -> SelectionViewParams {
+    // Snapshot the current theme so we can restore on cancel.
+    let original_theme = highlight::current_syntax_theme();
+
+    let entries = highlight::list_available_themes(codex_home);
+    let codex_home_owned = codex_home.map(Path::to_path_buf);
+
+    // Resolve the effective theme name: honor explicit config only when it is
+    // currently available; otherwise fall back to configured/default selection
+    // so opening `/theme` does not auto-preview an unrelated first entry.
+    let effective_name = if let Some(name) = current_name
+        && entries.iter().any(|entry| entry.name == name)
+    {
+        name.to_string()
+    } else {
+        highlight::configured_theme_name()
+    };
+
+    // Track the index of the current theme so we can pre-select it.
+    let mut initial_idx = None;
+
+    let items: Vec<SelectionItem> = entries
+        .iter()
+        .enumerate()
+        .map(|(idx, entry)| {
+            let display_name = if entry.is_custom {
+                format!("{} (custom)", entry.name)
+            } else {
+                entry.name.clone()
+            };
+            let is_current = entry.name == effective_name;
+            if is_current {
+                initial_idx = Some(idx);
+            }
+            let name_for_action = entry.name.clone();
+            SelectionItem {
+                name: display_name,
+                is_current,
+                dismiss_on_select: true,
+                search_value: Some(entry.name.clone()),
+                actions: vec![Box::new(move |tx| {
+                    tx.send(AppEvent::SyntaxThemeSelected {
+                        name: name_for_action.clone(),
+                    });
+                })],
+                ..Default::default()
+            }
+        })
+        .collect();
+
+    // Derive preview targets from the final `items` list (not from `entries`)
+    // so preview ordering stays aligned if item construction/sorting changes.
+    let preview_theme_names: Vec<Option<String>> =
+        items.iter().map(|item| item.search_value.clone()).collect();
+    let preview_home = codex_home_owned.clone();
+    let on_selection_changed = Some(Box::new(move |idx: usize, _tx: &_| {
+        if let Some(Some(name)) = preview_theme_names.get(idx)
+            && let Some(theme) = highlight::resolve_theme_by_name(name, preview_home.as_deref())
+        {
+            highlight::set_syntax_theme(theme);
+        }
+    })
+        as Box<dyn Fn(usize, &crate::app_event_sender::AppEventSender) + Send + Sync>);
+
+    // Restore original theme on cancel.
+    let on_cancel = Some(Box::new(move |_tx: &_| {
+        highlight::set_syntax_theme(original_theme.clone());
+    })
+        as Box<dyn Fn(&crate::app_event_sender::AppEventSender) + Send + Sync>);
+    SelectionViewParams {
+        title: Some("Select Syntax Theme".to_string()),
+        subtitle: Some(theme_picker_subtitle(
+            codex_home_owned.as_deref(),
+            terminal_width,
+        )),
+        footer_hint: Some(standard_popup_hint_line()),
+        items,
+        is_searchable: true,
+        search_placeholder: Some("Type to filter themes...".to_string()),
+        initial_selected_idx: initial_idx,
+        side_content: Box::new(ThemePreviewWideRenderable),
+        side_content_width: SideContentWidth::Half,
+        side_content_min_width: WIDE_PREVIEW_MIN_WIDTH,
+        stacked_side_content: Some(Box::new(ThemePreviewNarrowRenderable)),
+        on_selection_changed,
+        on_cancel,
+        ..Default::default()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+    use ratatui::style::Modifier;
+
+    fn render_buffer(renderable: &dyn Renderable, width: u16, height: u16) -> Buffer {
+        let area = Rect::new(0, 0, width, height);
+        let mut buf = Buffer::empty(area);
+        renderable.render(area, &mut buf);
+        buf
+    }
+
+    fn render_lines(renderable: &dyn Renderable, width: u16, height: u16) -> Vec<String> {
+        let buf = render_buffer(renderable, width, height);
+        (0..height)
+            .map(|row| {
+                let mut line = String::new();
+                for col in 0..width {
+                    let symbol = buf[(col, row)].symbol();
+                    if symbol.is_empty() {
+                        line.push(' ');
+                    } else {
+                        line.push_str(symbol);
+                    }
+                }
+                line
+            })
+            .collect()
+    }
+
+    fn first_non_space_style_after_marker(buf: &Buffer, row: u16, width: u16) -> Option<Modifier> {
+        let marker_col = (0..width)
+            .find(|&col| buf[(col, row)].symbol() == "-" || buf[(col, row)].symbol() == "+")?;
+        for col in marker_col + 1..width {
+            if buf[(col, row)].symbol() != " " {
+                return Some(buf[(col, row)].style().add_modifier);
+            }
+        }
+        None
+    }
+
+    fn preview_line_number(line: &str) -> Option<usize> {
+        let trimmed = line.trim_start();
+        let digits_len = trimmed.chars().take_while(char::is_ascii_digit).count();
+        if digits_len == 0 {
+            return None;
+        }
+        let digits = &trimmed[..digits_len];
+        if !trimmed[digits_len..].starts_with(' ') {
+            return None;
+        }
+        digits.parse::<usize>().ok()
+    }
+
+    fn preview_line_marker(line: &str) -> Option<char> {
+        let trimmed = line.trim_start();
+        let digits_len = trimmed.chars().take_while(char::is_ascii_digit).count();
+        if digits_len == 0 {
+            return None;
+        }
+        let mut chars = trimmed[digits_len..].chars();
+        if chars.next()? != ' ' {
+            return None;
+        }
+        chars.next()
+    }
+
+    #[test]
+    fn theme_picker_uses_half_width_with_stacked_fallback_preview() {
+        let params = build_theme_picker_params(None, None, None);
+        assert_eq!(params.side_content_width, SideContentWidth::Half);
+        assert_eq!(params.side_content_min_width, WIDE_PREVIEW_MIN_WIDTH);
+        assert!(params.stacked_side_content.is_some());
+    }
+
+    #[test]
+    fn theme_picker_items_include_search_values_for_preview_mapping() {
+        let params = build_theme_picker_params(None, None, None);
+        assert!(
+            params.items.iter().all(|item| item.search_value.is_some()),
+            "theme picker preview mapping relies on item search_value to stay aligned with final item order"
+        );
+    }
+
+    #[test]
+    fn wide_preview_renders_all_lines_with_vertical_center_and_left_inset() {
+        let lines = render_lines(&ThemePreviewWideRenderable, 80, 20);
+        let numbered_rows: Vec<usize> = lines
+            .iter()
+            .enumerate()
+            .filter_map(|(idx, line)| preview_line_number(line).map(|_| idx))
+            .collect();
+        let total_preview_lines = WIDE_PREVIEW_ROWS.len();
+
+        assert_eq!(numbered_rows.len(), total_preview_lines);
+        let first_row = *numbered_rows
+            .first()
+            .expect("expected at least one preview row");
+        let last_row = *numbered_rows
+            .last()
+            .expect("expected at least one preview row");
+        assert!(
+            first_row > 0,
+            "expected top padding before centered preview"
+        );
+        assert!(
+            last_row < 19,
+            "expected bottom padding after centered preview"
+        );
+
+        let first_line = &lines[first_row];
+        assert!(
+            first_line.starts_with("  31  fn summarize"),
+            "expected wide preview to start after a 2-char inset"
+        );
+
+        let markers: Vec<char> = lines
+            .iter()
+            .filter_map(|line| preview_line_marker(line))
+            .collect();
+        assert!(
+            markers.contains(&'+'),
+            "expected wide preview to include at least one addition line"
+        );
+        assert!(
+            markers.contains(&'-'),
+            "expected wide preview to include at least one removal line"
+        );
+    }
+
+    #[test]
+    fn narrow_preview_renders_single_add_and_single_remove_in_four_lines() {
+        let lines = render_lines(&ThemePreviewNarrowRenderable, 80, 6);
+        let numbered_lines: Vec<usize> = lines
+            .iter()
+            .filter_map(|line| preview_line_number(line))
+            .collect();
+        let markers: Vec<char> = lines
+            .iter()
+            .filter_map(|line| preview_line_marker(line))
+            .collect();
+
+        assert_eq!(numbered_lines, vec![12, 13, 13, 14]);
+        assert_eq!(markers.len(), 4);
+        assert_eq!(markers.iter().filter(|&&m| m == '+').count(), 1);
+        assert_eq!(markers.iter().filter(|&&m| m == '-').count(), 1);
+        let first_numbered = lines
+            .iter()
+            .find(|line| preview_line_number(line).is_some())
+            .expect("expected at least one rendered preview row");
+        assert!(
+            first_numbered.starts_with("12  fn greet"),
+            "expected narrow preview line numbers to start at the left edge"
+        );
+    }
+
+    #[test]
+    fn deleted_preview_code_uses_dim_overlay_like_real_diff_renderer() {
+        let width = 80;
+        let height = 6;
+        let buf = render_buffer(&ThemePreviewNarrowRenderable, width, height);
+        let lines = render_lines(&ThemePreviewNarrowRenderable, width, height);
+        let deleted_row = lines
+            .iter()
+            .enumerate()
+            .find_map(|(row, line)| (preview_line_marker(line) == Some('-')).then_some(row as u16))
+            .expect("expected a deleted preview row");
+        let modifiers = first_non_space_style_after_marker(&buf, deleted_row, width)
+            .expect("expected code text after diff marker");
+        assert!(
+            modifiers.contains(Modifier::DIM),
+            "expected deleted preview code to be dimmed"
+        );
+    }
+
+    #[test]
+    fn subtitle_uses_tilde_path_when_codex_home_under_home_directory() {
+        let home = dirs::home_dir().expect("home directory should be available");
+        let codex_home = home.join(".codex");
+
+        let subtitle = theme_picker_subtitle(Some(&codex_home), Some(200));
+
+        assert!(subtitle.contains("~"));
+        assert!(subtitle.contains("directory"));
+    }
+
+    #[test]
+    fn subtitle_falls_back_when_tilde_path_subtitle_is_too_wide() {
+        let home = dirs::home_dir().expect("home directory should be available");
+        let long_segment = "a".repeat(120);
+        let codex_home = home.join(long_segment).join(".codex");
+
+        let subtitle = theme_picker_subtitle(Some(&codex_home), Some(140));
+
+        assert_eq!(subtitle, PREVIEW_FALLBACK_SUBTITLE);
+    }
+
+    #[test]
+    fn subtitle_falls_back_to_preview_instructions_without_tilde_path() {
+        let subtitle = theme_picker_subtitle(None, None);
+        assert_eq!(subtitle, PREVIEW_FALLBACK_SUBTITLE);
+    }
+
+    #[test]
+    fn subtitle_falls_back_for_94_column_terminal_side_by_side_layout() {
+        let home = dirs::home_dir().expect("home directory should be available");
+        let codex_home = home.join(".codex");
+
+        let subtitle = theme_picker_subtitle(Some(&codex_home), Some(94));
+
+        assert_eq!(subtitle, PREVIEW_FALLBACK_SUBTITLE);
+    }
+
+    #[test]
+    fn unavailable_configured_theme_falls_back_to_configured_or_default_selection() {
+        let configured_or_default_theme = highlight::configured_theme_name();
+        let params = build_theme_picker_params(Some("not-a-real-theme"), None, Some(120));
+        let selected_idx = params
+            .initial_selected_idx
+            .expect("expected selected index for active fallback theme");
+        let selected_name = params.items[selected_idx]
+            .search_value
+            .as_deref()
+            .expect("expected search value to contain canonical theme name");
+
+        assert_eq!(selected_name, configured_or_default_theme);
+    }
+}
Author	SHA1	Message	Date
Eric Traut	a281880f37	Ignore syntect unmaintained advisories in cargo-deny	2026-02-21 14:48:48 -08:00
Felipe Coury	dd654ca0b2	chore(tui): Cargo.lock update from main	2026-02-21 19:28:15 -03:00
Felipe Coury	6444115730	chore(tui): removed kebab-case info on theme description	2026-02-21 19:28:02 -03:00
Felipe Coury	55c961040c	fix(tui): address syntax-theme review feedback	2026-02-21 19:21:19 -03:00
Felipe Coury	486f5850ca	chore(tui): Cargo.lock update from main	2026-02-21 19:21:19 -03:00
Felipe Coury	44a7ba0dda	feat(tui): harden theme lock recovery and ordering	2026-02-21 19:21:19 -03:00
Felipe Coury	18d62ac80f	feat(tui): harden theme fallback contracts and diff wrapping	2026-02-21 19:21:19 -03:00
Felipe Coury	75c819e54a	docs(tui): theme picker, highlight lifecycle, diff rendering contracts	2026-02-21 19:21:19 -03:00
Felipe Coury	5986719f96	fix(tui): resolve clippy -D warnings findings	2026-02-21 19:21:19 -03:00
Felipe Coury	801ae5e979	feat(tui): reuse diff renderer for theme preview	2026-02-21 19:21:19 -03:00
Felipe Coury	89891de55a	feat(tui): diff visual gallery snapshots with syntax-highlighted cases	2026-02-21 19:21:19 -03:00
Felipe Coury	46021a3591	fix(tui): wrap syntax spans before first overflowing wide character	2026-02-21 19:21:19 -03:00
Felipe Coury	c510eec9f8	feat(tui): fallback to active theme when configured theme is unavailable	2026-02-21 19:21:18 -03:00
Felipe Coury	8c4bfa78f7	feat(tui): width-aware theme subtitle fallback and 94x35 regression test	2026-02-21 19:21:18 -03:00
Felipe Coury	f72e7bf529	feat(tui): live theme override and dynamic CODEX_HOME paths set_theme_override now updates the runtime theme immediately instead of only setting the OnceLock, enabling live switching from /theme. Replace hardcoded ~/.codex/themes references with resolved $CODEX_HOME/themes paths in warnings, schema docs, and picker subtitle.	2026-02-21 19:21:17 -03:00
Felipe Coury	987db6aaf6	fix(tui): only fire on_selection_changed when actual item changes Extract selected_actual_idx() helper and guard move_up/move_down so the callback is skipped when wrapping doesn't change the selected item (e.g. single-item lists). Adds a test for the single-item case.	2026-02-21 19:21:17 -03:00
Felipe Coury	0066e85f0f	fix(tui): preserve syntect parser state across diff hunk lines Highlight each hunk as a single block instead of per-line so that multiline constructs (e.g. strings spanning multiple lines) get correct syntax coloring. Adds a regression test.	2026-02-21 19:21:17 -03:00
Felipe Coury	197131762b	tui: harden theme picker cancel and custom theme handling	2026-02-21 19:21:17 -03:00
Felipe Coury	85e1e7bf5a	tui: sync theme picker state and validate custom themes	2026-02-21 19:21:16 -03:00
Felipe Coury	f4ac1f09b3	tui: refine theme preview alignment in wide and narrow layouts	2026-02-21 19:20:48 -03:00
Felipe Coury	8ca13e5d56	tui: fix theme preview layout and terminal background rendering	2026-02-21 19:20:48 -03:00
Felipe Coury	ea57beb959	feat(tui): add /theme picker with live syntax-highlighted preview Add a `/theme` slash command that opens an interactive picker listing all bundled and custom (.tmTheme) syntax themes. The picker shows a live-preview code snippet below the list that re-highlights as the user navigates, and restores the original theme on cancel. Key changes: - ListSelectionView gains `footer_content`, `on_selection_changed`, and `on_cancel` to support rich preview and lifecycle callbacks - highlight.rs: swap global Theme from OnceLock to RwLock for live swapping; add resolve/list/set/current helpers for theme management - New theme_picker module with ThemePreviewRenderable and picker builder - diff_render: make DiffLineType and helpers pub(crate); fix rename highlighting to use destination extension - markdown_render: fix CRLF double-newlines and info-string metadata parsing for fenced code blocks	2026-02-21 19:20:48 -03:00
Felipe Coury	976dd6831e	fix(tui): configure syntax theme from final config, not initial `set_theme_override` was called with `initial_config.tui_theme` before onboarding/resume/fork could reload config. Because the theme state lives in a `OnceLock`, it was permanently locked to the initial value. Move the call to after the last possible config reload so the theme and its warning always reflect the final session config.	2026-02-21 19:20:48 -03:00
Felipe Coury	d32e05d4e5	fix(tui): treat tabs as visible width, preserve theme warning on resume - Tabs in syntax-highlighted diff spans now count as 4 columns instead of zero, so tab-indented code wraps correctly in the diff view. - Move theme warning injection to after the last possible config reload (session resume/fork) so the ⚠ banner is not silently discarded.	2026-02-21 19:20:48 -03:00
Felipe Coury	06d4c95d35	style(tui): rustfmt	2026-02-21 19:20:48 -03:00
Felipe Coury	3cd1301409	fix(tui): trim CRLF in highlighted spans, enforce diff size guardrails Two fixes from code review: 1. `trim_end_matches('\n')` left a stray `\r` on CRLF inputs, which propagated into rendered code blocks and diffs. Now strips both `\r` and `\n`. 2. Unified diff highlighting called `highlight_code_to_styled_spans` per line, bypassing the global size guardrails (max bytes/lines). On large patches this triggered thousands of parser initializations. Added a pre-check on aggregate patch size that skips highlighting when limits are exceeded.	2026-02-21 19:20:48 -03:00
Felipe Coury	e7d4e828c3	feat(tui): support custom .tmTheme files from ~/.codex/themes/ Extend theme resolution so `theme = "foo"` checks ~/.codex/themes/foo.tmTheme before falling back to auto-detection. Surface unresolved theme names as a ⚠ startup warning in the TUI via the existing startup_warnings pipeline.	2026-02-21 19:20:47 -03:00
Felipe Coury	32ff9e89ed	fix(tui): fix fallback phantom line and diff wrap at span boundaries Two fixes: 1. highlight.rs: The fallback path used split('\n') which produces a phantom empty trailing element for inputs ending in '\n' (as pulldown-cmark emits for code blocks). Switch to lines() which handles trailing newlines correctly. 2. diff_render.rs: wrap_styled_spans only flushed the current line when col >= max_cols AND the current span had remaining content. This missed the case where one span ends exactly at max_cols and the next span has content — the next span's first character was appended to the already-full line. Remove the !remaining.is_empty() guard so the line flushes at span boundaries too.	2026-02-21 19:20:47 -03:00
Felipe Coury	f00f7d49dc	fix(tui): preserve trailing blank lines in fenced code blocks trim_end_matches('\n') stripped all trailing newlines from the code block buffer before highlighting, discarding intentional blank lines authored inside fences. pulldown-cmark appends exactly one trailing '\n' to the text content, and LinesWithEndings handles it correctly as a line terminator, so no trimming is needed. Remove the trim to preserve user-authored blank lines faithfully.	2026-02-21 19:20:47 -03:00
Felipe Coury	82fc47e317	feat(tui): add `theme` config setting, suppress underline from themes Add `[tui] theme = "..."` config option that lets users override the auto-detected syntax highlighting theme with any of the 32 bundled two-face themes by kebab-case name. Invalid names log a warning and fall back to adaptive detection. Also suppress FontStyle::UNDERLINE in convert_style — themes like Dracula mark type scopes with underline which produces distracting underlines on type/module names in terminal output.	2026-02-21 19:20:47 -03:00
Felipe Coury	9878b734a0	refactor(tui): remove normalize_lang, delegate to two-face directly two-face's ~250 language syntax set resolves almost all names and extensions on its own. Remove the redundant normalize_lang layer and keep only 3 patched aliases (golang, python3, shell) that two-face cannot resolve. This enables highlighting for any language in bat's syntax set (elixir, haskell, scala, dart, php, html, css, etc.) without needing explicit entries.	2026-02-21 19:20:47 -03:00
Felipe Coury	5f92cb4e58	feat(tui): use two-face for extended syntax highlighting and adaptive theme Replace syntect's default ~40 language set with two-face's bat-sourced ~250 language set, adding support for TypeScript, TSX, Kotlin, Swift, and Zig. Auto-detect terminal background to pick CatppuccinMocha (dark) or CatppuccinLatte (light). Suppress italic modifier by default since many terminals render it poorly.	2026-02-21 19:20:47 -03:00
Felipe Coury	d97bd689dd	chore: remove orphaned tree-sitter-highlight workspace dependency No crate references it after the TUI switched to syntect.	2026-02-21 19:20:47 -03:00
Felipe Coury	252b574c65	fix(tui): update exec approval snapshot for syntect bash highlighting The exec approval modal's command line now gets syntax-colored spans from syntect (base16-ocean.dark) instead of tree-sitter-bash.	2026-02-21 19:20:47 -03:00
Felipe Coury	1ddc3d7b00	fix(tui): wrap syntax-highlighted diff lines, add highlight guardrails Integrate syntax highlighting into diff rendering and markdown code blocks, with proper line wrapping that preserves styled spans. - Add detect_lang_for_path() for extension-based language detection - Syntax-aware diff rendering for Add/Delete/Update file changes - wrap_styled_spans() splits long highlighted lines across display rows - Buffer fenced code blocks in markdown_render for batch highlighting - Add snapshot tests for highlighted diff wrapping - Replace code_block_unhighlighted test with 3 syntax color assertions	2026-02-21 19:20:47 -03:00
Felipe Coury	776e4b0aa8	feat(tui): add multi-language syntax highlighting via syntect Replace tree-sitter-bash and tree-sitter-highlight with syntect for code highlighting. Syntect's HighlightLines API resolves overlapping spans internally, significantly simplifying the implementation. - Add syntect workspace dependency, remove tree-sitter-bash/highlight from tui - Rewrite highlight.rs with syntect singletons (SyntaxSet + base16-ocean.dark theme) - Normalize language aliases (js→javascript, py→python, rs→rust, etc.) - Multi-strategy syntax lookup: token, name, case-insensitive name, extension - Add guardrails: skip highlighting for inputs >512KB or >10K lines - Comprehensive tests for style conversion, language resolution, content preservation	2026-02-21 19:20:47 -03:00