opencode/packages/app/src/components/titlebar-tab-nav.css

[data-titlebar-tab] [data-slot="tab-close"] {
  position: absolute;
  top: 4px;
  right: 4px;
  display: flex;
  height: 20px;
  width: 20px;
  align-items: center;
  justify-content: center;
}

[data-titlebar-tab] {
  --tab-base: var(--v2-background-bg-deep);
  --tab-overlay: transparent;
  background: linear-gradient(var(--tab-overlay), var(--tab-overlay)), var(--tab-base);
}

[data-titlebar-tab]:is(:hover, :has(> [data-slot="tab-link"]:focus-visible)):not([data-state="pressed"]):not(
    [data-dragging="true"]
  ):not([data-editing="true"]) {
  --tab-base: var(--v2-background-bg-layer-02);
  --tab-overlay: var(--v2-overlay-simple-overlay-hover);
}

[data-titlebar-tab]:is([data-state="pressed"], [data-dragging="true"], [data-editing="true"]) {
  --tab-base: var(--v2-background-bg-layer-02);
  --tab-overlay: var(--v2-overlay-simple-overlay-pressed);
}

[data-titlebar-tab]:is(:hover, [data-state="pressed"]) [data-slot="tab-close"] {
  background: linear-gradient(var(--tab-overlay), var(--tab-overlay)), var(--tab-base);
}

[data-titlebar-tab][data-editing="true"] [data-slot="tab-close"] {
  display: none;
}

[data-titlebar-tab-list] {
  gap: 6px;
}

[data-titlebar-tab-slot] {
  --tab-separator: var(--v2-background-bg-layer-03);
  position: relative;
}

[data-color-scheme="dark"] [data-titlebar-tab-slot] {
  --tab-separator: var(--v2-background-bg-layer-02);
}

[data-titlebar-tab-slot]:not(:first-child):not([data-active="true"])::before {
  content: "";
  position: absolute;
  top: 8px;
  left: -3.75px;
  width: 1.5px;
  height: 12px;
  border-radius: 9999px;
  background: var(--tab-separator);
}

[data-titlebar-tab-slot][data-active="true"] + [data-titlebar-tab-slot]::before {
  display: none;
}

[data-titlebar-tab-slot]:not([data-active="true"]):has([data-titlebar-tab]:hover)::before,
[data-titlebar-tab-slot]:not([data-active="true"]):has([data-titlebar-tab]:hover) + [data-titlebar-tab-slot]::before {
  display: none;
}

[data-titlebar-tab][data-title-overflow="true"]:not([data-editing="true"]) [data-slot="tab-link"] {
  --tab-title-fade-offset: 4px;
  -webkit-mask-image: linear-gradient(
    to right,
    black 0,
    black calc(100% - var(--tab-title-fade-offset) - 16px),
    transparent calc(100% - var(--tab-title-fade-offset)),
    transparent 100%
  );
  mask-image: linear-gradient(
    to right,
    black 0,
    black calc(100% - var(--tab-title-fade-offset) - 16px),
    transparent calc(100% - var(--tab-title-fade-offset)),
    transparent 100%
  );
}

[data-titlebar-tab][data-title-overflow="true"]:is(:hover, [data-active="true"]):not([data-editing="true"])
  [data-slot="tab-link"] {
  --tab-title-fade-offset: 24px;
}

[data-titlebar-tab][data-title-overflow="true"]:not(:hover):not([data-active="true"]):not([data-editing="true"])
  [data-slot="tab-link"] {
  padding-right: 0;
}

[data-titlebar-tab] [data-slot="tab-title"] {
  min-width: 0;
}

[data-titlebar-tab][data-editing="true"] [data-slot="tab-title"] {
  min-width: 0;
  max-width: 100%;
  flex: 1 1 auto;
  overflow-x: auto;
  overflow-y: hidden;
  white-space: nowrap;
  scrollbar-width: none;
}

[data-titlebar-tab][data-editing="true"] [data-slot="tab-title"]::-webkit-scrollbar {
  display: none;
}

@container (max-width: 64px) {
  [data-titlebar-tab-link] {
    justify-content: center;
    gap: 0;
    padding-inline: 0;
  }

  [data-titlebar-tab-title] {
    display: none;
  }

  [data-slot="tab-close"] {
    right: auto;
    left: 50%;
    transform: translateX(-50%);
  }
}