:root {
    /* Light Theme Default */
    --bg-base: #f8fafc;
    --bg-surface: #ffffff;
    --bg-surface-hover: #f1f5f9;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --text-inverse: #ffffff;
    --accent-primary: #6366f1;
    --accent-primary-hover: #4f46e5;
    --accent-secondary: #8b5cf6;
    --border-color: #e2e8f0;
    --danger: #ef4444;
    --danger-hover: #dc2626;
    --success: #10b981;
    --warning: #f59e0b;

    --accent-primary-alpha-10: rgba(99, 102, 241, 0.1);
    --accent-primary-alpha-20: rgba(99, 102, 241, 0.2);
    --accent-primary-alpha-40: rgba(99, 102, 241, 0.4);
    
    --accent-secondary-alpha-10: rgba(139, 92, 246, 0.1);
    --accent-secondary-alpha-20: rgba(139, 92, 246, 0.2);
    
    --danger-alpha-10: rgba(239, 68, 68, 0.1);
    --danger-alpha-20: rgba(239, 68, 68, 0.2);

    --table-hover-bg: rgba(0, 0, 0, 0.02);
    --modal-overlay: rgba(15, 23, 42, 0.5);

    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);

    --login-gradient-start: var(--bg-base);
    --login-gradient-end: #e2e8f0;

    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --transition: 0.2s ease;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-base: #0f172a;
        --bg-surface: #1e293b;
        --bg-surface-hover: #334155;
        --text-primary: #f8fafc;
        --text-secondary: #94a3b8;
        --text-muted: #64748b;
        --border-color: #334155;
        --table-hover-bg: rgba(255, 255, 255, 0.02);
        --modal-overlay: rgba(15, 23, 42, 0.8);
        --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
        --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.5), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
        --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
        --login-gradient-start: var(--bg-base);
        --login-gradient-end: #1e1b4b;
    }
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-base);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 600;
}

/* Layout */
.app-container {
    display: flex;
    height: 100vh;
    overflow: hidden;
}

/* Sidebar */
.sidebar {
    width: 260px;
    background-color: var(--bg-surface);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 1.5rem 0;
    z-index: 10;
}

.logo {
    padding: 0 1.5rem;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    font-family: var(--font-heading);
    color: var(--accent-primary);
}

.nav-menu {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    padding: 0 1rem;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.875rem 1rem;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.nav-item:hover {
    background-color: var(--bg-surface-hover);
    color: var(--text-primary);
}

.nav-item.active {
    background-color: var(--accent-primary-alpha-10);
    color: var(--accent-primary);
    border-left: 3px solid var(--accent-primary);
}

.nav-item i {
    width: 20px;
    text-align: center;
    font-size: 1.125rem;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.top-bar {
    height: 72px;
    background-color: var(--bg-base);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2rem;
}

.top-bar h1 {
    font-size: 1.5rem;
    color: var(--text-primary);
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 500;
}

.user-profile img {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--border-color);
}

.view-container {
    flex: 1;
    overflow-y: auto;
    padding: 2rem;
}

.view {
    display: none;
    animation: fadeIn 0.3s ease;
}

.view.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(5px); }
    to { opacity: 1; transform: translateY(0); }
}

/* View Headers */
.view-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.view-header h2 {
    font-size: 1.5rem;
}

/* Cards & Stats */
.card {
    background-color: var(--bg-surface);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
}

.stat-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.stat-icon {
    width: 60px;
    height: 60px;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, var(--accent-primary-alpha-20), var(--accent-secondary-alpha-20));
    color: var(--accent-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
}

.stat-info h3 {
    font-size: 0.875rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.25rem;
}

.stat-info p {
    font-size: 2rem;
    font-weight: 700;
    font-family: var(--font-heading);
}

/* Tables */
.table-responsive {
    overflow-x: auto;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
}

.data-table th, .data-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.data-table th {
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.data-table tbody tr {
    transition: var(--transition);
}

.data-table tbody tr:hover {
    background-color: var(--table-hover-bg);
}

.data-table tbody tr:last-child td {
    border-bottom: none;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    border-radius: var(--radius-md);
    font-weight: 500;
    font-family: var(--font-body);
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    outline: none;
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: 0.75rem;
}

.btn-primary {
    background-color: var(--accent-primary);
    color: var(--text-inverse);
}

.btn-primary:hover {
    background-color: var(--accent-primary-hover);
    box-shadow: 0 0 10px var(--accent-primary-alpha-40);
}

.btn-secondary {
    background-color: var(--bg-surface-hover);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background-color: var(--border-color);
}

.btn-danger {
    background-color: var(--danger-alpha-10);
    color: var(--danger);
    padding: 0.375rem 0.75rem;
}

.btn-danger:hover {
    background-color: var(--danger);
    color: var(--text-inverse);
}

/* Forms & Modals */
.modal {
    display: none;
    position: fixed;
    inset: 0;
    background-color: var(--modal-overlay);
    backdrop-filter: blur(4px);
    z-index: 100;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
    animation: fadeIn 0.2s ease;
}

.modal-content {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    width: 100%;
    max-width: 500px;
    padding: 2rem;
    box-shadow: var(--shadow-lg);
}

.modal-lg .modal-content {
    max-width: 700px;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.modal-header h2 {
    font-size: 1.5rem;
}

.close-modal {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    transition: var(--transition);
}

.close-modal:hover {
    color: var(--text-primary);
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-row {
    display: flex;
    gap: 1.25rem;
}

.form-row .form-group {
    flex: 1;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
}

input, select {
    width: 100%;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    background-color: var(--bg-base);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 0.875rem;
    transition: var(--transition);
}

input:focus, select:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 2px var(--accent-primary-alpha-20);
}

.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

/* Stops Section specific */
.stops-section {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px dashed var(--border-color);
}

.stops-section h3 {
    margin-bottom: 0.25rem;
    font-size: 1.125rem;
}

.help-text {
    color: var(--text-secondary);
    font-size: 0.8125rem;
    margin-bottom: 1rem;
}

.stop-input-group {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
    align-items: center;
}

.stop-number {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background-color: var(--bg-surface-hover);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-secondary);
}

/* Utilities */
.badge {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 500;
}

.badge-route {
    background-color: var(--accent-secondary-alpha-10);
    color: var(--accent-secondary);
    border: 1px solid var(--accent-secondary-alpha-20);
}

.badge-bus {
    background-color: var(--accent-primary-alpha-10);
    color: var(--accent-primary);
    border: 1px solid var(--accent-primary-alpha-20);
}

/* --- Mobile / App-like Responsiveness --- */
@media (max-width: 768px) {
    /* App Layout */
    .app-container {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        height: auto;
        padding: 0.5rem 0;
        flex-direction: row;
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        border-right: none;
        border-top: 1px solid var(--border-color);
        z-index: 50;
        box-shadow: 0 -4px 10px rgba(0, 0, 0, 0.05);
    }

    .sidebar .logo {
        display: none; /* Hide logo in bottom nav */
    }

    .nav-menu {
        flex-direction: row;
        justify-content: space-around;
        padding: 0;
        width: 100%;
        gap: 0;
    }
    
    .nav-menu > div[style] {
        margin: 0 !important;
        padding: 0 !important;
        display: flex;
        flex: 1 1 0px;
    }

    .nav-item {
        flex-direction: column;
        padding: 0.5rem 0.25rem;
        gap: 0.25rem;
        font-size: 0.65rem;
        text-align: center;
        border-radius: 0;
        flex: 1 1 0px;
        border-left: none !important;
        border-top: 3px solid transparent;
    }

    .nav-item i {
        font-size: 1.25rem;
    }
    
    .nav-item.active {
        border-top: 3px solid var(--accent-primary);
        background-color: transparent;
        color: var(--accent-primary);
    }
    
    /* Top Bar & Content */
    .main-content {
        padding-bottom: 70px; /* Space for bottom nav */
    }

    .top-bar {
        padding: 0 1rem;
        height: 60px;
    }

    .top-bar h1 {
        font-size: 1.25rem;
    }

    .user-profile span {
        display: none; /* Hide admin name on mobile */
    }
    
    .user-profile img {
        width: 32px;
        height: 32px;
    }

    .view-container {
        padding: 1rem;
    }

    /* Cards & Grids */
    .stat-cards {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .view-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    
    .view-header button {
        width: 100%;
    }

    /* Forms */
    .form-row {
        flex-direction: column;
        gap: 0;
    }

    /* Modals - Bottom Sheet effect */
    .modal {
        align-items: flex-end;
    }
    
    .modal-content {
        max-width: 100%;
        border-radius: var(--radius-xl) var(--radius-xl) 0 0;
        padding: 1.5rem;
        border-bottom: none;
        border-left: none;
        border-right: none;
        max-height: 90vh;
        overflow-y: auto;
        animation: slideUpModal 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
    }

    .modal-lg .modal-content {
        max-width: 100%;
    }

    @keyframes slideUpModal {
        from { transform: translateY(100%); }
        to { transform: translateY(0); }
    }
    
    .table-responsive {
        /* Allow edge-to-edge scroll inside cards */
        margin: 0 -1.5rem;
        padding: 0 1.5rem;
        width: calc(100% + 3rem);
    }
}