opencode/packages/ui/src/components/scroll-fade.css

[data-component="scroll-fade"] {
  overflow: auto;
  overscroll-behavior: contain;
  scrollbar-width: none;
  box-sizing: border-box;
  color: inherit;
  font: inherit;
  -ms-overflow-style: none;
  
  &::-webkit-scrollbar {
    display: none;
  }

  &[data-direction="horizontal"] {
    overflow-x: auto;
    overflow-y: hidden;

    /* Both fades */
    &[data-fade-start][data-fade-end] {
      mask-image: linear-gradient(
        to right,
        transparent,
        black var(--scroll-fade-start),
        black calc(100% - var(--scroll-fade-end)),
        transparent
      );
      -webkit-mask-image: linear-gradient(
        to right,
        transparent,
        black var(--scroll-fade-start),
        black calc(100% - var(--scroll-fade-end)),
        transparent
      );
    }

    /* Only start fade */
    &[data-fade-start]:not([data-fade-end]) {
      mask-image: linear-gradient(
        to right,
        transparent,
        black var(--scroll-fade-start),
        black 100%
      );
      -webkit-mask-image: linear-gradient(
        to right,
        transparent,
        black var(--scroll-fade-start),
        black 100%
      );
    }

    /* Only end fade */
    &:not([data-fade-start])[data-fade-end] {
      mask-image: linear-gradient(
        to right,
        black 0%,
        black calc(100% - var(--scroll-fade-end)),
        transparent
      );
      -webkit-mask-image: linear-gradient(
        to right,
        black 0%,
        black calc(100% - var(--scroll-fade-end)),
        transparent
      );
    }
  }

  &[data-direction="vertical"] {
    overflow-y: auto;
    overflow-x: hidden;

    &[data-fade-start][data-fade-end] {
      mask-image: linear-gradient(
        to bottom,
        transparent,
        black var(--scroll-fade-start),
        black calc(100% - var(--scroll-fade-end)),
        transparent
      );
      -webkit-mask-image: linear-gradient(
        to bottom,
        transparent,
        black var(--scroll-fade-start),
        black calc(100% - var(--scroll-fade-end)),
        transparent
      );
    }

    /* Only start fade */
    &[data-fade-start]:not([data-fade-end]) {
      mask-image: linear-gradient(
        to bottom,
        transparent,
        black var(--scroll-fade-start),
        black 100%
      );
      -webkit-mask-image: linear-gradient(
        to bottom,
        transparent,
        black var(--scroll-fade-start),
        black 100%
      );
    }

    /* Only end fade */
    &:not([data-fade-start])[data-fade-end] {
      mask-image: linear-gradient(
        to bottom,
        black 0%,
        black calc(100% - var(--scroll-fade-end)),
        transparent
      );
      -webkit-mask-image: linear-gradient(
        to bottom,
        black 0%,
        black calc(100% - var(--scroll-fade-end)),
        transparent
      );
    }
  }
}