@keyframes titlebar-tab-fade-left { from { visibility: hidden; } to { visibility: visible; } } @keyframes titlebar-tab-fade-right { from { visibility: visible; } to { visibility: hidden; } } /* The narrow ranges preserve the binary thresholds of scrollLeft > 0 and remaining scroll distance > 1px. Hidden defaults make an inactive timeline (no overflow) a no-op. Unsupported browsers also degrade to no fades. */ [data-slot="titlebar-tabs"] { container-type: inline-size; timeline-scope: --titlebar-tabs-scroll; [data-slot^="titlebar-tabs-fade-"] { visibility: hidden; } } @container (max-width: 64px) { [data-slot="titlebar-tab-link"] { justify-content: center; gap: 0; padding-inline: 0; } [data-slot="titlebar-tab-title"] { display: none; } } @supports (animation-timeline: --titlebar-tabs-scroll) and (timeline-scope: --titlebar-tabs-scroll) { [data-slot="titlebar-tabs-scroll"] { scroll-timeline: --titlebar-tabs-scroll x; } [data-slot="titlebar-tabs-fade-left"] { animation: titlebar-tab-fade-left linear both; animation-timeline: --titlebar-tabs-scroll; animation-range: 0 0.1px; } [data-slot="titlebar-tabs-fade-right"] { animation: titlebar-tab-fade-right linear both; animation-timeline: --titlebar-tabs-scroll; animation-range: calc(100% - 1.1px) calc(100% - 1px); } }