/*
 * `<x-tabs>`, `<x-tab>`: M3's tabs (PrimaryNavigationTabTokens.kt, SecondaryNavigationTabTokens.kt,
 * androidx Compose Material 3, Apache-2.0; docs/reference/m3/components-navigation-selection-inputs.md
 * § Tabs) — a tablist of tabs at least 48px tall on the surface over an outline-variant divider
 * (64px when a primary tab stacks its icon over its label), title-small labels in on-surface-variant, the chosen tab's in
 * primary (primary tabs) or on-surface (secondary tabs).
 *
 *   [data-md-tabs]                 min-width: 0
 *     [data-md-tabs-bar]           role="tablist"; data-md-variant, data-md-stacked,
 *                                  data-md-scrollable
 *       [data-md-tab]              role="tab"
 *         [data-md-tab-content]    [data-md-icon] (optional), [data-md-tab-label],
 *                                  [data-md-tab-indicator]
 *           [data-md-tab-label]    [data-md-tab-text], [data-md-badge] (optional)
 *   [data-md-tab-panel]            role="tabpanel", hidden server-side until chosen (N-05)
 *
 * "Labels: single row by default; may wrap to a max second line if needed with truncation, or use
 * scrollable tabs to give longer titles more room" (§ Tabs, "Behaviour and guidelines"). A fixed
 * tab shares the row equally, so its label keeps one row while it fits its share, then wraps to a
 * second line and truncates that one with an ellipsis. 48px (64px stacked) is the tab's minimum,
 * not its height: the tab grows to hold the second line, and the bar's flex row stretches every
 * tab to the tallest, so the tabs keep one height, each content box fills its tab, and every
 * indicator stays on the divider under its tab's content. A scrollable tab is as wide as its label
 * and keeps it on one row, the room M3 gives longer titles instead.
 *
 * The active indicator is drawn in every tab and shown under the chosen one, so it is right before
 * Alpine starts and after a morph: 3px with rounded top corners under the content of a primary tab
 * (at least 24px wide, inset 2px at each side — N-18), 2px across the whole of a secondary one.
 * When the choice changes, a view transition moves it from the old tab to the new (resources/js/tabs.js),
 * as M3's slides.
 *
 * The bar scrolls sideways, so it clips whatever leaves it — including the focus ring, which the
 * rest of the package draws 3px thick 2px outside the element (tokens/state.css). `--tabs-ring` is
 * the room that takes: the bar carries it as padding on every side, and the state layer and the
 * indicator reach back out into it, so the divider still sits against the tabs and the indicator
 * still sits on the divider (N-20). That makes the bar 10px taller than M3's 48px tab. A scrollable
 * set's first tab is offset 52dp from the leading edge, so it reads as scrollable (N-10). A link
 * marked `aria-current="page"` (`<x-section-nav>`'s tabs) takes the active indicator and colour
 * exactly as `aria-selected="true"` does (N-21).
 */

@layer material.reset, material.tokens, material.base, material.layout, material.components, material.text, material.visibility;

@import './icon.css';
@import './badge.css';

@layer material.components {
    [data-md-tabs] {
        min-width: 0;
    }

    [data-md-tabs-bar] {
        --tabs-ring: 5px;

        position: relative;
        display: flex;
        overflow-x: auto;
        overscroll-behavior-x: contain;
        padding: var(--tabs-ring);
        scroll-padding-inline: var(--tabs-ring);
        border-bottom: 1px solid var(--md-sys-color-outline-variant);
        scrollbar-width: thin;
    }

    /* "Offset the first scrollable tab 52dp from the leading edge so it's clear that more content
       is available" (N-10). Logical, so a right-to-left page mirrors it. */
    [data-md-tabs-bar][data-md-scrollable] {
        padding-inline-start: 52px;
        scroll-padding-inline-start: 52px;
    }

    /* A section nav's links sit in list items that share the width. */
    [data-md-tabs-bar] > li {
        flex: 1 1 0%;
    }

    [data-md-tabs-bar] > li > [data-md-tab] {
        flex: 1 1 0%;
    }

    [data-md-tab] {
        position: relative;
        display: flex;
        flex: 1 1 0%;
        min-width: 90px;
        min-height: 48px;
        align-items: center;
        justify-content: center;
        padding-inline: var(--md-sys-measurement-space200);
        color: var(--md-sys-color-on-surface-variant);
        cursor: pointer;
        outline: none;
        font: var(--md-sys-typescale-title-sm);
        letter-spacing: var(--md-sys-typescale-title-sm-tracking);
        white-space: nowrap;
        transition-property: color;
        transition-duration: var(--md-sys-motion-effects-fast-duration);
        transition-timing-function: var(--md-sys-motion-effects-fast);
    }

    [data-md-tabs-bar][data-md-scrollable] > li,
    [data-md-tabs-bar][data-md-scrollable] [data-md-tab] {
        flex: none;
    }

    [data-md-tabs-bar][data-md-stacked] [data-md-tab] {
        min-height: 64px;
    }

    /* The state layer covers the tab and the ring's room around it, so the wash meets the divider. */
    [data-md-tab]::before {
        content: '';
        position: absolute;
        inset-block: calc(-1 * var(--tabs-ring));
        inset-inline: 0;
        pointer-events: none;
        transition-property: background-color;
        transition-duration: var(--md-sys-motion-effects-fast-duration);
        transition-timing-function: var(--md-sys-motion-effects-fast);
    }

    @media (hover: hover) {
        [data-md-tab]:hover {
            color: var(--md-sys-color-on-surface);
        }

        [data-md-tab]:hover::before {
            background-color: color-mix(in srgb, var(--md-sys-color-on-surface) 8%, transparent);
        }
    }

    [data-md-tab]:focus-visible::before,
    [data-md-tab]:active::before {
        background-color: color-mix(in srgb, var(--md-sys-color-on-surface) 10%, transparent);
    }

    [data-md-tab]:focus-visible {
        color: var(--md-sys-color-on-surface);
        outline: 3px solid var(--md-sys-color-secondary);
        outline-offset: 2px;
    }

    /* A link-based bar marks the page with aria-current, not aria-selected; both are the chosen
       tab, and both take the variant's active colour (N-21). */
    [data-md-tab]:is([aria-selected='true'], [aria-current='page']) {
        color: var(--md-sys-color-primary);
    }

    [data-md-tabs-bar][data-md-variant='secondary'] [data-md-tab]:is([aria-selected='true'], [aria-current='page']) {
        color: var(--md-sys-color-on-surface);
    }

    [data-md-tab]:disabled {
        color: color-mix(in srgb, var(--md-sys-color-on-surface) 38%, transparent);
        cursor: default;
    }

    [data-md-tab]:disabled::before {
        background-color: transparent;
    }

    /* Stretched rather than 100% tall, so it fills a tab that grew past its minimum too, and the
       primary indicator at its foot lands on the divider in every tab of the bar. */
    [data-md-tab-content] {
        position: relative;
        display: inline-flex;
        align-self: stretch;
        min-width: 24px;
        align-items: center;
        justify-content: center;
        gap: var(--md-sys-measurement-space100);
    }

    [data-md-tabs-bar][data-md-stacked] [data-md-tab-content] {
        flex-direction: column;
        gap: var(--md-sys-measurement-space25);
    }

    [data-md-tab-label] {
        display: inline-flex;
        min-width: 0;
        align-items: center;
        gap: var(--md-sys-measurement-space75);
    }

    /* A fixed tab's label: one row while it fits, then a second, truncated (the M3 line above).
       The tab's own nowrap still holds the badge and a scrollable tab's label to one row. */
    [data-md-tabs-bar]:not([data-md-scrollable]) [data-md-tab-text] {
        display: -webkit-box;
        min-width: 0;
        overflow: hidden;
        -webkit-box-orient: vertical;
        -webkit-line-clamp: 2;
        text-align: center;
        text-overflow: ellipsis;
        white-space: normal;
    }

    /* Primary indicators are inset 2dp at each side (N-18); both variants sit on the divider, which
       the ring's room has pushed below the tab. */
    [data-md-tab-indicator] {
        position: absolute;
        inset-inline: 2px;
        bottom: calc(-1 * var(--tabs-ring));
        height: 3px;
        border-radius: 3px 3px 0 0;
        background-color: var(--md-sys-color-primary);
        opacity: 0;
        pointer-events: none;
        view-transition-class: material-tab-indicator;
    }

    /* A secondary tab's indicator spans the tab, not its content. */
    [data-md-tabs-bar][data-md-variant='secondary'] [data-md-tab-content] {
        position: static;
    }

    [data-md-tabs-bar][data-md-variant='secondary'] [data-md-tab-indicator] {
        inset-inline: 0;
        height: 2px;
        border-radius: 0;
    }

    [data-md-tab]:is([aria-selected='true'], [aria-current='page']) [data-md-tab-indicator] {
        opacity: 1;
        view-transition-name: var(--tabs-indicator);
    }

    /* pt-6, before the rewrite: the panel's content stands clear of the bar above it. */
    [data-md-tab-panel] {
        padding-top: var(--md-sys-measurement-space300);
        outline: none;
    }

    ::view-transition-group(*.material-tab-indicator) {
        animation-duration: var(--md-sys-motion-spatial-default-duration);
        animation-timing-function: var(--md-sys-motion-spatial-default);
    }
}