/* * ``: M3 Expressive's flexible navigation bar, three to five destinations * pinned to the bottom of a compact or medium window (NavigationBarTokens.kt, androidx Compose * Material 3, Apache-2.0, and the layout of ShortNavigationBar.kt; * docs/reference/m3/components-navigation-selection-inputs.md § Navigation Bar). * * [data-md-navigation-bar] 64px in surface-container; data-md-tall (80px), * data-md-hide-on-scroll and data-md-hidden * [data-md-navigation-bar-items] equal widths below 600px; centred with Compose's * calculateCenteredContentHorizontalPadding from it * [data-md-navigation-bar-item] navigation-bar-item.css * * `data-md-tall` is `NavigationBarTokens.TallContainerHeight`, 80px against the short bar's 64 * (`ContainerHeight`) — Missing until this rewrite. It keeps the vertical, icon-over-label item * layout at every width, so every rule below that only the short bar's horizontal layout needs * says `:not([data-md-tall])` first. * * `data-md-hide-on-scroll` is M3's scrolling behaviour, also Missing until now: "hides on * scroll-down, reappears on scroll-up… never hide it while a screen reader is active" * (§ Navigation Bar/Behaviour). resources/js/navigation.js drives `data-md-hidden` and never hides * the bar while a snackbar, a bottom sheet or a drawer rests on its edge — those are anchored to * its bottom edge and would slide with it — and focus reaching the bar brings it back, the web's * nearest equivalent of "a screen reader is active". It slides on the default spatial spring, * which reduced motion zeroes along with every other duration token. * * The item's own indicator, pill and state layer (shared with the rail item) are * navigation-bar-item.css and navigation-item.css. */ @layer material.reset, material.tokens, material.base, material.layout, material.components, material.text, material.visibility; @layer material.components { [data-md-navigation-bar] { container-type: inline-size; padding-inline: var(--material-safe-left, env(safe-area-inset-left)) var(--material-safe-right, env(safe-area-inset-right)); padding-bottom: var(--material-safe-bottom, env(safe-area-inset-bottom)); background-color: var(--md-sys-color-surface-container); color: var(--md-sys-color-on-surface-variant); } [data-md-navigation-bar-items] { display: flex; min-height: 64px; margin-inline: auto; } [data-md-navigation-bar][data-md-tall] [data-md-navigation-bar-items] { min-height: 80px; } [data-md-navigation-bar][data-md-hide-on-scroll] { transition: translate var(--md-sys-motion-spatial-default-duration) var(--md-sys-motion-spatial-default); } [data-md-navigation-bar][data-md-hide-on-scroll][data-md-hidden] { translate: 0 100%; } /* From 600px (M3's medium window, the bar's own width): icon and label side by side in a 40px pill, the items gathered in the middle with Centered arrangement's own padding. The short bar only — a tall bar is the vertical layout everywhere. */ @container (width >= 600px) { [data-md-navigation-bar]:not([data-md-tall]) [data-md-navigation-bar-items] { width: calc(10% * (var(--navigation-bar-count, 7) + 3)); min-width: fit-content; max-width: 100%; } [data-md-navigation-bar]:not([data-md-tall]) [data-md-navigation-bar-items]:has(> :last-child:nth-child(1)) { --navigation-bar-count: 1; } [data-md-navigation-bar]:not([data-md-tall]) [data-md-navigation-bar-items]:has(> :last-child:nth-child(2)) { --navigation-bar-count: 2; } [data-md-navigation-bar]:not([data-md-tall]) [data-md-navigation-bar-items]:has(> :last-child:nth-child(3)) { --navigation-bar-count: 3; } [data-md-navigation-bar]:not([data-md-tall]) [data-md-navigation-bar-items]:has(> :last-child:nth-child(4)) { --navigation-bar-count: 4; } [data-md-navigation-bar]:not([data-md-tall]) [data-md-navigation-bar-items]:has(> :last-child:nth-child(5)) { --navigation-bar-count: 5; } [data-md-navigation-bar]:not([data-md-tall]) [data-md-navigation-bar-items]:has(> :last-child:nth-child(6)) { --navigation-bar-count: 6; } } /* * A bar that has slid off the bottom of the window is no longer there to clear, so the offset * everything pinned to the bottom reads drops to the bottom safe area and whatever the * application has docked on the bar — a `fab` button, the snackbar and the page's own bottom * padding all follow it down and come back up with it. Layered now, unlike before this * rewrite: used to publish --material-bottom-bar with a Tailwind utility, which * no rule in any layer could outrank regardless of specificity; now scaffold.css publishes it * itself in `material.layout` (layout/scaffold.css), a layer this file's own * `material.components` always outranks by declaration order alone — the same reason * toolbar.css's and fab.css's overrides only have to beat another `material.components` rule, * not chase a Tailwind utility out of the cascade. Keyed on `data-md-scaffold`, the hook the * scaffold renders on its root, not `data-app-shell`, which that rewrite also retired. */ [data-md-scaffold]:has([data-md-navigation-bar][data-md-hide-on-scroll][data-md-hidden]) { --material-bottom-bar: calc(var(--material-safe-bottom, env(safe-area-inset-bottom)) + var(--material-bottom-extra, 0px)); } }