/* ═══════════════════════════════════════════════════════════════════════════════
   OmniTransport — Responsive & Accessibility Stylesheet
   Covers: mobile (360px), tablet (768px), laptop (1024px), desktop (1366px+)
   ═══════════════════════════════════════════════════════════════════════════════ */

/* ─── Focus Indicators (Accessibility) ─── */
:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
    border-radius: var(--radius-sm);
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* ─── Skip Navigation (Screen Reader) ─── */
.skip-link {
    position: absolute;
    top: -100px;
    left: 0;
    background: var(--primary);
    color: #fff;
    padding: 8px 16px;
    z-index: 100000;
    font-weight: 600;
    border-radius: 0 0 var(--radius-sm) 0;
    transition: top 0.2s;
}

.skip-link:focus {
    top: 0;
}

/* ─── Hamburger Menu Button (Mobile) ─── */
.mobile-menu-toggle {
    display: none;
    position: fixed;
    top: 12px;
    left: 12px;
    z-index: 10001;
    background: var(--bg-sidebar);
    color: #F8FAFC;
    border: none;
    border-radius: var(--radius-md);
    width: 42px;
    height: 42px;
    font-size: 1.2rem;
    cursor: pointer;
    box-shadow: var(--shadow-md);
    transition: var(--transition-fast);
}

.mobile-menu-toggle:hover {
    background: var(--primary);
}

/* ─── Sidebar Overlay (Mobile) ─── */
.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 9998;
}

/* ─── Form Label Accessibility ─── */
label {
    display: block;
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

/* ─── Empty States ─── */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 3rem 1.5rem;
    text-align: center;
    color: var(--text-muted);
    background: var(--bg-card);
    border: 1px dashed var(--border-color);
    border-radius: var(--radius-lg);
}

.empty-state i {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--text-dimmed);
}

.empty-state h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.empty-state p {
    font-size: 0.82rem;
    max-width: 300px;
}

/* ─── Loading Skeleton ─── */
.skeleton {
    background: linear-gradient(90deg, #f1f5f9 25%, #e2e8f0 50%, #f1f5f9 75%);
    background-size: 200% 100%;
    animation: skeleton-shimmer 1.5s infinite;
    border-radius: var(--radius-sm);
}

@keyframes skeleton-shimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* ─── Reduced Motion Preference ─── */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    .skeleton {
        animation: none;
        background: #e2e8f0;
    }
}

/* ═══════════════════════════════════════════════════════════
   TABLET — max-width: 1024px
   ═══════════════════════════════════════════════════════════ */
@media (max-width: 1024px) {
    .sidebar {
        width: 200px;
    }

    .main-content {
        margin-left: 200px;
    }

    .billing-grid,
    .dispatch-grid,
    .fleet-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }
}

/* ═══════════════════════════════════════════════════════════
   MOBILE — max-width: 768px
   Sidebar collapses to overlay, single column layout
   ═══════════════════════════════════════════════════════════ */
@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
        align-items: center;
        justify-content: center;
    }

    .sidebar {
        position: fixed;
        left: -280px;
        top: 0;
        bottom: 0;
        width: 260px;
        z-index: 9999;
        transition: left 0.3s ease;
    }

    .sidebar.open {
        left: 0;
    }

    .sidebar-overlay.visible {
        display: block;
    }

    .main-content {
        margin-left: 0;
        padding: 60px 12px 12px;
        width: 100%;
    }

    /* Single column grids on mobile */
    .billing-grid,
    .dispatch-grid,
    .fleet-grid,
    .active-dispatches-grid {
        grid-template-columns: 1fr;
    }

    /* Booking form: stack fields vertically */
    .dispatch-form-grid,
    .booking-form-grid {
        grid-template-columns: 1fr;
        gap: 10px;
    }

    /* Map fills more space */
    #map {
        height: 50vh;
        min-height: 300px;
    }

    /* Tables become scrollable */
    .table-responsive {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }

    /* Modal full-width on mobile */
    .modal-content,
    .dialog-card {
        width: 95vw;
        max-width: 95vw;
        margin: 10px auto;
    }

    /* Header adjustments */
    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }

    .section-header .btn {
        width: 100%;
    }

    /* Tab navigation: horizontal scroll if many tabs */
    .nav-menu {
        overflow-x: auto;
        white-space: nowrap;
    }
}

/* ═══════════════════════════════════════════════════════════
   SMALL MOBILE — max-width: 480px
   ═══════════════════════════════════════════════════════════ */
@media (max-width: 480px) {
    body {
        font-size: 13px;
    }

    .main-content {
        padding: 56px 8px 8px;
    }

    .card, .dispatch-card, .billing-card {
        padding: 12px;
    }

    h2, h3 {
        font-size: 1rem;
    }

    /* Invoice modal: ensure scrollable on small screens */
    .invoice-modal-content {
        max-height: 85vh;
        overflow-y: auto;
    }
}

/* ═══════════════════════════════════════════════════════════
   ACCESSIBILITY — High Contrast Mode
   ═══════════════════════════════════════════════════════════ */
@media (forced-colors: active) {
    .nav-item.active {
        border: 2px solid CanvasText;
    }

    .btn {
        border: 1px solid CanvasText;
    }
}

/* ─── Keyboard Navigation Visible ─── */
.nav-item:focus-visible {
    outline: 2px solid #fff;
    outline-offset: -2px;
}

/* ─── Scrollbar Styling (subtle) ─── */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--text-dimmed);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* ─── Print Styles ─── */
@media print {
    .sidebar,
    .mobile-menu-toggle,
    .nav-menu,
    .sidebar-footer {
        display: none !important;
    }

    .main-content {
        margin-left: 0 !important;
    }

    body {
        background: #fff;
        color: #000;
    }
}