/* ==============================================
   Filter Sheet Styles
   Bottom sheet drawer for timeline filtering
   ============================================== */

/* ==============================================
   Floating Filter Button (FAB)
   ============================================== */

.filter-fab {
    position: absolute;
    bottom: calc(var(--space-4) + var(--sa-bottom));
    left: var(--space-4);
    width: 48px;
    height: 48px;
    border-radius: 50%;
    /* glass class provides background, blur, border */
    color: var(--color-text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 50;
    transition: background var(--transition-base), transform var(--transition-base);
    box-shadow: var(--shadow-md);
}

.filter-fab[hidden] {
    display: none;
}

/* glass-interactive class provides hover/press scale feedback */

.filter-fab:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

.filter-fab.has-filters {
    background: var(--color-accent-bg);
    border-color: var(--color-accent);
}

.filter-fab svg {
    width: 20px;
    height: 20px;
}

/* Filter count badge */
.filter-badge {
    position: absolute;
    top: -4px;
    right: -4px;
    min-width: 18px;
    height: 18px;
    padding: 0 5px;
    background: var(--color-accent);
    color: #fff;
    font-size: 11px;
    font-weight: var(--font-weight-semibold);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
}

.filter-badge[hidden] {
    display: none;
}


/* ==============================================
   Filter Sheet Overlay & Container
   ============================================== */

.filter-overlay {
    position: fixed;
    inset: 0;
    background: var(--color-overlay-light);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-base);
    z-index: var(--z-nav);
}

.filter-overlay.visible {
    opacity: 1;
    /* Don't block pointer events - allows scrolling content behind overlay */
    /* Click-to-close is handled via document click listener */
    pointer-events: none;
}

.filter-sheet {
    --sheet-bottom: calc(var(--space-3) + var(--sa-bottom));

    display: flex;
    flex-direction: column;
    position: fixed;
    left: 50%;
    bottom: var(--sheet-bottom);
    max-width: 600px;
    width: calc(100% - var(--space-6));
    max-height: 70vh !important; /* INVESTIGATE: Why do we need !important here */
    overflow: hidden;

    /* Glassmorphism - matches nav-drawer and datejump-drawer */
    background: rgba(20, 20, 22, 0.85);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);

    /* Hidden by default, slides up */
    visibility: hidden;
    transform: translateX(-50%) translateY(calc(100% + var(--sheet-bottom)));
    transition: transform 0.2s ease, visibility 0s 0.2s;
    z-index: calc(var(--z-nav) + 3);
}

.filter-sheet.visible {
    visibility: visible;
    transform: translateX(-50%) translateY(0);
    transition: transform 0.2s ease, visibility 0s;
}


/* ==============================================
   Filter Sheet Header
   ============================================== */

.filter-sheet-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-3) var(--space-4);
    border-bottom: 1px solid var(--color-border);
    flex-shrink: 0;
}

.filter-sheet-title {
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text-primary);
}

.filter-sheet-close {
    background: none;
    border: none;
    color: var(--color-text-muted);
    font-size: 1.5em;
    cursor: pointer;
    padding: 0;
    width: 42px;
    height: 42px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.filter-sheet-close span {
    transform: translateY(-1px);
    display: inline-block;
}

/* Desktop hover */
@media (hover: hover) and (pointer: fine) {
    .filter-sheet-close:hover {
        background: rgba(255, 255, 255, 0.08);
        color: var(--color-text-primary);
    }
}

/* Touch feedback */
@media (hover: none) and (pointer: coarse) {
    .filter-sheet-close:active {
        background: rgba(255, 255, 255, 0.12);
        transform: scale(0.92);
        transition: transform 0.06s ease-out;
    }
}

.filter-sheet-close:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}


/* ==============================================
   Filter Sheet Content
   ============================================== */

.filter-sheet-content {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: var(--space-4) var(--space-5);
    -webkit-overflow-scrolling: touch;
}

.filter-section {
    margin-bottom: var(--space-2);
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-lg);
    padding: var(--space-2);
}

.filter-section:last-child {
    margin-bottom: 0;
}

.filter-section-header {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    width: 100%;
    background: rgba(255, 255, 255, 0.05);
    border: none;
    padding: var(--space-3);
    border-radius: var(--radius-md);
    cursor: pointer;
    color: inherit;
    font: inherit;
}

.filter-section-header:has(+ .filter-options:not([hidden])) {
    margin-bottom: var(--space-3);
}

.filter-section-chevron {
    color: var(--color-text-muted);
    transition: transform var(--transition-fast);
    flex-shrink: 0;
}

.filter-section-chevron.expanded {
    transform: rotate(90deg);
}

.filter-section-title {
    font-size: var(--font-size-xs);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.filter-section-count {
    font-size: var(--font-size-xs);
    color: var(--color-accent);
    margin-left: auto;
}

.filter-options {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

.filter-options[hidden] {
    display: none;
}


/* ==============================================
   Filter Option (Checkbox Row)
   ============================================== */

.filter-option {
    background-color: transparent;
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: background var(--transition-fast);
}

/* Desktop hover */
@media (hover: hover) and (pointer: fine) {
    .filter-option:hover {
        background: rgba(255, 255, 255, 0.05);
    }
}

/* Touch feedback */
@media (hover: none) and (pointer: coarse) {
    .filter-option:active {
        background: rgba(255, 255, 255, 0.08);
        transition: background 0.06s ease-out;
    }
}

.filter-option-label {
    flex: 1;
    font-size: var(--font-size-sm);
    color: var(--color-text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.filter-option-count {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    font-variant-numeric: tabular-nums;
    background: rgba(255, 255, 255, 0.08);
    padding: 4px 8px;
    border-radius: var(--radius-full);
}

/* Nested city list */
.filter-cities {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
    padding-left: var(--space-6);
    margin-top: var(--space-1);
}

.filter-cities[hidden] {
    display: none;
}

/* Country row with expand toggle */
.filter-option-country {
    position: relative;
}

.filter-expand-toggle {
    background: none;
    border: none;
    color: var(--color-text-muted);
    cursor: pointer;
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    border-radius: var(--radius-sm);
    padding: 0;
    transition: transform var(--transition-fast);
}

.filter-expand-toggle.expanded {
    transform: rotate(90deg);
}


/* ==============================================
   Filter Sheet Footer
   ============================================== */

.filter-sheet-footer {
    padding: var(--space-3) var(--space-5) var(--space-4);
    border-top: 1px solid var(--color-border);
}

.filter-sheet-footer .core-btn {
    width: 100%;
}


/* ==============================================
   Filter Empty State
   ============================================== */

.filter-empty {
    text-align: center;
    padding: var(--space-8) var(--space-4);
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
}


/* ==============================================
   Responsive Adjustments
   ============================================== */

@media (max-width: 480px) {
    .filter-fab {
        width: 44px;
        height: 44px;
    }

    .filter-fab svg {
        width: 18px;
        height: 18px;
    }

    .filter-sheet {
        max-height: 80vh;
    }

    .filter-sheet-content {
        padding: var(--space-3) var(--space-4);
    }

    .filter-sheet-footer {
        padding: var(--space-3) var(--space-4);
    }
}

/* Desktop - slightly larger bottom spacing */
@media (min-width: 768px) {
    .filter-sheet {
        --sheet-bottom: calc(var(--space-4) + var(--sa-bottom));
        max-height: 60vh;
    }
}


/* ==============================================
   Reduced Motion Support
   ============================================== */

@media (prefers-reduced-motion: reduce) {
    .filter-fab,
    .filter-sheet,
    .filter-overlay {
        transition: none;
    }
}