/* ─────────────────────────────────────────────────────────────────────────────
   MD3 Components — shared component layer (Material Design 3)

   Complements /css/shared.css (tokens), /css/app-shell.css (.shell-header /
   .shell-icon-btn / .shell-btn / .shell-snackbar), /css/modal.css (dialogs)
   and /css/dropdown.css (custom selects). Load AFTER shared.css.

   Classes are namespaced `md-` to coexist with Tailwind utilities. All colors
   come from --md-* tokens and resolve in BOTH light and dark schemes.
───────────────────────────────────────────────────────────────────────────── */

/* ── Buttons ─────────────────────────────────────────────────────────────── */
.md-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    height: 40px;
    padding: 0 24px;
    font: inherit;
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 0.01em;
    border: none;
    border-radius: var(--md-shape-full);
    cursor: pointer;
    text-decoration: none;
    white-space: nowrap;
    user-select: none;
    position: relative;
    overflow: hidden;
    isolation: isolate;
    transition: box-shadow var(--md-duration-s) var(--md-easing-standard),
                background var(--md-duration-s) var(--md-easing-standard),
                color var(--md-duration-s) var(--md-easing-standard);
}
/* state layer */
.md-btn::after {
    content: '';
    position: absolute;
    inset: 0;
    z-index: -1;
    background: currentColor;
    opacity: 0;
    transition: opacity var(--md-duration-s) var(--md-easing-standard);
}
.md-btn:hover::after  { opacity: 0.08; }
.md-btn:active::after { opacity: 0.12; }
.md-btn:active { transform: scale(0.99); }
.md-btn .material-symbols-outlined { font-size: 18px; }
.md-btn:disabled,
.md-btn[aria-disabled="true"] {
    cursor: not-allowed;
    background: color-mix(in srgb, var(--md-on-surface) 12%, transparent);
    color: color-mix(in srgb, var(--md-on-surface) 38%, transparent);
    box-shadow: none;
    transform: none;
}
.md-btn:disabled::after { display: none; }

.md-btn-filled {
    background: var(--md-primary);
    color: var(--md-on-primary);
}
.md-btn-filled:hover { box-shadow: var(--md-elevation-1); }
.md-btn-tonal {
    background: var(--md-secondary-container);
    color: var(--md-on-secondary-container);
}
.md-btn-outlined {
    background: transparent;
    color: var(--md-primary);
    border: 1px solid var(--md-outline);
}
.md-btn-text {
    background: transparent;
    color: var(--md-primary);
    padding: 0 12px;
}
.md-btn-danger {
    background: var(--md-error);
    color: var(--md-on-error);
}
.md-btn-danger-tonal {
    background: var(--md-error-container);
    color: var(--md-on-error-container);
}
.md-btn-sm { height: 32px; padding: 0 16px; font-size: 13px; }
.md-btn-lg { height: 48px; padding: 0 28px; font-size: 15px; border-radius: var(--md-shape-lg); }

/* ── Icon button (round, 40px hit target minimum) ────────────────────────── */
.md-icon-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    flex-shrink: 0;
    background: transparent;
    color: var(--md-on-surface-variant);
    border: none;
    border-radius: var(--md-shape-full);
    cursor: pointer;
    text-decoration: none;
    position: relative;
    overflow: hidden;
    isolation: isolate;
    transition: color var(--md-duration-s) var(--md-easing-standard),
                background var(--md-duration-s) var(--md-easing-standard);
}
.md-icon-btn::after {
    content: '';
    position: absolute;
    inset: 0;
    z-index: -1;
    background: currentColor;
    opacity: 0;
    transition: opacity var(--md-duration-s) var(--md-easing-standard);
}
.md-icon-btn:hover { color: var(--md-on-surface); }
.md-icon-btn:hover::after  { opacity: 0.08; }
.md-icon-btn:active::after { opacity: 0.12; }
.md-icon-btn .material-symbols-outlined { font-size: 22px; }
.md-icon-btn-tonal {
    background: var(--md-secondary-container);
    color: var(--md-on-secondary-container);
}
.md-icon-btn-filled {
    background: var(--md-primary);
    color: var(--md-on-primary);
}
.md-icon-btn:disabled {
    color: color-mix(in srgb, var(--md-on-surface) 38%, transparent);
    cursor: not-allowed;
}

/* ── FAB ─────────────────────────────────────────────────────────────────── */
.md-fab {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    height: 56px;
    min-width: 56px;
    padding: 0 20px;
    background: var(--md-primary-container);
    color: var(--md-on-primary-container);
    border: none;
    border-radius: var(--md-shape-lg);
    cursor: pointer;
    font: inherit;
    font-size: 14px;
    font-weight: 600;
    box-shadow: var(--md-elevation-2);
    transition: box-shadow var(--md-duration-s) var(--md-easing-standard),
                transform var(--md-duration-s) var(--md-easing-standard);
}
.md-fab:hover  { box-shadow: var(--md-elevation-3); }
.md-fab:active { transform: scale(0.97); }
.md-fab .material-symbols-outlined { font-size: 24px; }

/* ── Cards ───────────────────────────────────────────────────────────────── */
.md-card {
    background: var(--md-surface-container-low);
    color: var(--md-on-surface);
    border-radius: var(--md-shape-md);
    transition: background var(--md-duration-s) var(--md-easing-standard),
                box-shadow var(--md-duration-s) var(--md-easing-standard),
                border-color var(--md-duration-s) var(--md-easing-standard);
}
.md-card-elevated { box-shadow: var(--md-elevation-1); }
.md-card-elevated:hover { box-shadow: var(--md-elevation-2); }
.md-card-filled { background: var(--md-surface-container-highest); }
.md-card-outlined {
    background: var(--md-surface);
    border: 1px solid var(--md-outline-variant);
}
.md-card-interactive { cursor: pointer; }
.md-card-interactive:hover { background: var(--md-surface-container); }

/* ── Text fields (simple outlined — label above input) ───────────────────── */
.md-field { display: flex; flex-direction: column; gap: 6px; }
.md-field > label {
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.4px;
    color: var(--md-on-surface-variant);
    margin-left: 4px;
}
.md-field > input,
.md-field > textarea,
.md-input {
    width: 100%;
    padding: 10px 16px;
    font: inherit;
    font-size: 14px;
    color: var(--md-on-surface);
    background: var(--md-surface-container-low);
    border: 1px solid var(--md-outline-variant);
    border-radius: var(--md-shape-sm);
    transition: border-color var(--md-duration-s) var(--md-easing-standard),
                background var(--md-duration-s) var(--md-easing-standard);
}
.md-field > input::placeholder,
.md-field > textarea::placeholder,
.md-input::placeholder { color: color-mix(in srgb, var(--md-on-surface-variant) 70%, transparent); }
.md-field > input:hover,
.md-field > textarea:hover,
.md-input:hover { border-color: var(--md-outline); }
.md-field > input:disabled,
.md-field > textarea:disabled,
.md-input:disabled {
    background: color-mix(in srgb, var(--md-on-surface) 4%, transparent);
    color: color-mix(in srgb, var(--md-on-surface) 38%, transparent);
    cursor: not-allowed;
}
.md-field-error > input,
.md-field-error > textarea,
.md-input.md-input-error { border-color: var(--md-error); }
.md-field-supporting {
    font-size: 12px;
    color: var(--md-on-surface-variant);
    margin-left: 4px;
}
.md-field-error .md-field-supporting { color: var(--md-error); }

/* ── Chips ───────────────────────────────────────────────────────────────── */
.md-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    height: 32px;
    padding: 0 14px;
    font-size: 13px;
    font-weight: 500;
    color: var(--md-on-surface-variant);
    background: transparent;
    border: 1px solid var(--md-outline-variant);
    border-radius: var(--md-shape-sm);
    cursor: pointer;
    user-select: none;
    white-space: nowrap;
    transition: background var(--md-duration-s) var(--md-easing-standard),
                color var(--md-duration-s) var(--md-easing-standard),
                border-color var(--md-duration-s) var(--md-easing-standard);
}
.md-chip:hover { background: var(--md-surface-container-high); }
.md-chip.selected,
.md-chip[aria-pressed="true"],
.md-chip[aria-selected="true"] {
    background: var(--md-secondary-container);
    color: var(--md-on-secondary-container);
    border-color: transparent;
}
.md-chip .material-symbols-outlined { font-size: 18px; }

/* ── List items ──────────────────────────────────────────────────────────── */
.md-list-item {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 10px 16px;
    min-height: 48px;
    color: var(--md-on-surface);
    border-radius: var(--md-shape-sm);
    cursor: pointer;
    text-decoration: none;
    transition: background var(--md-duration-s) var(--md-easing-standard);
}
.md-list-item:hover { background: var(--md-surface-container-high); }
.md-list-item.selected {
    background: var(--md-secondary-container);
    color: var(--md-on-secondary-container);
}
.md-list-item-headline { font-size: 14px; font-weight: 500; }
.md-list-item-supporting {
    font-size: 12px;
    color: var(--md-on-surface-variant);
}

/* ── Misc ────────────────────────────────────────────────────────────────── */
.md-divider {
    border: none;
    border-top: 1px solid var(--md-outline-variant);
    margin: 8px 0;
}
.md-badge {
    display: inline-flex;
    align-items: center;
    height: 20px;
    padding: 0 8px;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.3px;
    border-radius: var(--md-shape-full);
    background: var(--md-secondary-container);
    color: var(--md-on-secondary-container);
    white-space: nowrap;
}
.md-badge-error   { background: var(--md-error-container);   color: var(--md-on-error-container); }
.md-badge-success { background: var(--md-success-container); color: var(--md-on-success-container); }
.md-badge-warning { background: var(--md-warning-container); color: var(--md-on-warning-container); }

/* Status banner (inline, non-modal error/info surface — pairs with the
   user-facing-errors rule: visible failure states, never console-only). */
.md-banner {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 14px 18px;
    font-size: 14px;
    border-radius: var(--md-shape-md);
    background: var(--md-surface-container-high);
    color: var(--md-on-surface);
    border: 1px solid var(--md-outline-variant);
}
.md-banner-error {
    background: var(--md-error-container);
    color: var(--md-on-error-container);
    border-color: transparent;
}
.md-banner-success {
    background: var(--md-success-container);
    color: var(--md-on-success-container);
    border-color: transparent;
}
.md-banner-warning {
    background: var(--md-warning-container);
    color: var(--md-on-warning-container);
    border-color: transparent;
}
.md-banner .material-symbols-outlined { font-size: 20px; flex-shrink: 0; margin-top: 1px; }

/* Tailwind v4 puts .hidden in @layer utilities, but .md-banner's display: flex
   is unlayered — unlayered styles beat layered ones regardless of specificity,
   so .hidden alone can't hide a banner. This scoped rule restores the expected
   behaviour. */
.md-banner.hidden { display: none; }

/* ── Switch (MD3 toggle) ─────────────────────────────────────────────────── */
.md-switch {
    display: inline-flex;
    align-items: center;
    gap: var(--md-space-2);
    cursor: pointer;
    user-select: none;
}
.md-switch input { position: absolute; opacity: 0; width: 0; height: 0; }
.md-switch-track {
    position: relative;
    width: 52px;
    height: 32px;
    border-radius: var(--md-shape-full);
    border: 2px solid var(--md-outline);
    background: var(--md-surface-container-high);
    transition: background var(--md-duration-s) var(--md-easing-standard),
                border-color var(--md-duration-s) var(--md-easing-standard);
}
.md-switch-thumb {
    position: absolute;
    top: 50%;
    left: 8px;
    transform: translateY(-50%);
    width: 16px;
    height: 16px;
    border-radius: var(--md-shape-full);
    background: var(--md-outline);
    transition: transform var(--md-duration-m) var(--md-easing-emphasized),
                width var(--md-duration-m) var(--md-easing-emphasized),
                height var(--md-duration-m) var(--md-easing-emphasized),
                background var(--md-duration-s) var(--md-easing-standard);
}
.md-switch input:checked ~ .md-switch-track {
    background: var(--md-primary);
    border-color: var(--md-primary);
}
.md-switch input:checked ~ .md-switch-track .md-switch-thumb {
    transform: translateY(-50%) translateX(20px);
    width: 24px;
    height: 24px;
    background: var(--md-on-primary);
}
.md-switch input:focus-visible ~ .md-switch-track {
    outline: var(--md-focus-ring-width) solid var(--md-focus-ring-color);
    outline-offset: 2px;
}

/* ── Linear Progress Indicator ──────────────────────────────────────────── */
.md-progress {
    width: 100%;
    height: 4px;
    background: var(--md-surface-container-highest);
    border-radius: var(--md-shape-full);
    overflow: hidden;
}
.md-progress-bar {
    height: 100%;
    background: var(--md-primary);
    border-radius: var(--md-shape-full);
    transition: width var(--md-duration-m) var(--md-easing-standard);
}
.md-progress-circular {
    display: inline-block;
    width: 36px;
    height: 36px;
    border: 3px solid color-mix(in srgb, var(--md-primary) 25%, transparent);
    border-top-color: var(--md-primary);
    border-radius: 50%;
    animation: md-spin 0.7s linear infinite;
}

/* ── Tooltip ────────────────────────────────────────────────────────────── */
.md-tooltip {
    position: absolute;
    bottom: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%);
    padding: 6px 10px;
    background: var(--md-inverse-surface);
    color: var(--md-inverse-on-surface);
    font-size: 12px;
    font-weight: 500;
    border-radius: var(--md-shape-xs);
    white-space: nowrap;
    pointer-events: none;
    opacity: 0;
    z-index: 100;
    transition: opacity var(--md-duration-s) var(--md-easing-standard);
}
[data-tooltip]:hover > .md-tooltip,
[data-tooltip]:focus-visible > .md-tooltip { opacity: 1; }

/* ── Navigation Rail (MD3 side navigation) ──────────────────────────────── */
.md-nav-rail {
    display: flex;
    flex-direction: column;
    gap: var(--md-space-1);
    padding: var(--md-space-2);
    width: 80px;
    flex-shrink: 0;
}
.md-nav-rail-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: var(--md-space-2) 0;
    border-radius: var(--md-shape-lg);
    color: var(--md-on-surface-variant);
    text-decoration: none;
    cursor: pointer;
    transition: background var(--md-duration-s) var(--md-easing-standard),
                color var(--md-duration-s) var(--md-easing-standard);
    position: relative;
}
.md-nav-rail-item:hover { background: var(--md-surface-container-high); }
.md-nav-rail-item.active { color: var(--md-on-surface); }
.md-nav-rail-item.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 32px;
    background: var(--md-primary);
    border-radius: var(--md-shape-full);
}
.md-nav-rail-item .material-symbols-outlined { font-size: 24px; }
.md-nav-rail-item-label { font-size: 11px; font-weight: 500; }

/* ── Segmented Button (MD3) ─────────────────────────────────────────────── */
.md-segmented-btn {
    display: inline-flex;
    border: 1px solid var(--md-outline);
    border-radius: var(--md-shape-full);
    overflow: hidden;
}
.md-segmented-btn-item {
    display: inline-flex;
    align-items: center;
    gap: var(--md-space-2);
    padding: 0 var(--md-space-4);
    height: 40px;
    font-size: 14px;
    font-weight: 500;
    color: var(--md-on-surface);
    background: transparent;
    border: none;
    border-right: 1px solid var(--md-outline);
    cursor: pointer;
    transition: background var(--md-duration-s) var(--md-easing-standard);
}
.md-segmented-btn-item:last-child { border-right: none; }
.md-segmented-btn-item:hover { background: var(--md-surface-container-high); }
.md-segmented-btn-item.selected {
    background: var(--md-secondary-container);
    color: var(--md-on-secondary-container);
}
.md-segmented-btn-item .material-symbols-outlined { font-size: 18px; }

/* ── Empty State ────────────────────────────────────────────────────────── */
.md-empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--md-space-3);
    padding: var(--md-space-12) var(--md-space-6);
    text-align: center;
    color: var(--md-on-surface-variant);
}
.md-empty-state .material-symbols-outlined {
    font-size: 48px;
    opacity: 0.4;
}
.md-empty-state-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--md-on-surface);
}
.md-empty-state-text {
    font-size: 14px;
    max-width: 320px;
}

/* ── Skeleton (loading placeholder) ─────────────────────────────────────── */
.md-skeleton {
    background: linear-gradient(
        90deg,
        var(--md-surface-container-high) 0%,
        var(--md-surface-container-highest) 50%,
        var(--md-surface-container-high) 100%
    );
    background-size: 200% 100%;
    animation: md-shimmer 1.4s linear infinite;
    border-radius: var(--md-shape-sm);
}