:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --success-color: #27ae60;
    --danger-color: #e74c3c;
    --warning-color: #f39c12;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --text-color: #212529;
    --text-muted: #6c757d;
    --border-color: #dee2e6;
    --sidebar-bg: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
    --sidebar-text: rgba(255,255,255,0.8);
    --sidebar-hover: rgba(255,255,255,0.1);
}

[data-theme="dark"] {
    /* Core Variables */
    --primary-color: #3498db;
    --secondary-color: #2980b9;
    --success-color: #2ecc71;
    --danger-color: #e74c3c;
    --warning-color: #f39c12;
    --bg-color: #1a1a1a;
    --card-bg: #2d2d2d;
    --text-color: #e0e0e0;
    --text-muted: #a0a0a0;
    --border-color: #404040;
    --sidebar-bg: linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 100%);
    --sidebar-text: rgba(255,255,255,0.9);
    --sidebar-hover: rgba(255,255,255,0.15);

    /* Bootstrap Overrides map */
    --bs-body-bg: var(--bg-color);
    --bs-body-color: var(--text-color);
    --bs-card-bg: var(--card-bg);
    --bs-border-color: var(--border-color);
    --bs-primary: var(--primary-color);
    --bs-secondary: var(--secondary-color);
    --bs-success: var(--success-color);
    --bs-info: #17a2b8;
    --bs-warning: var(--warning-color);
    --bs-danger: var(--danger-color);
}

/* Dark Mode Specific Overrides */
[data-theme="dark"] .bg-light {
    background-color: rgba(255, 255, 255, 0.05) !important;
    color: var(--text-color) !important;
}

[data-theme="dark"] .bg-white {
    background-color: var(--card-bg) !important;
    color: var(--text-color) !important;
}

[data-theme="dark"] .text-muted {
    color: #b0b0b0 !important;
}

[data-theme="dark"] .text-dark {
    color: #e0e0e0 !important;
}

[data-theme="dark"] .border {
    border-color: var(--border-color) !important;
}

/* Dark Mode Alerts */
[data-theme="dark"] .alert-info {
    background-color: rgba(52, 152, 219, 0.15);
    color: #85c1e9;
    border-color: rgba(52, 152, 219, 0.2);
}

[data-theme="dark"] .alert-success {
    background-color: rgba(46, 204, 113, 0.15);
    color: #82e0aa;
    border-color: rgba(46, 204, 113, 0.2);
}

[data-theme="dark"] .alert-warning {
    background-color: rgba(241, 196, 15, 0.15);
    color: #f7dc6f;
    border-color: rgba(241, 196, 15, 0.2);
}

[data-theme="dark"] .alert-danger {
    background-color: rgba(231, 76, 60, 0.15);
    color: #f1948a;
    border-color: rgba(231, 76, 60, 0.2);
}

[data-theme="dark"] .alert-primary {
    background-color: rgba(52, 152, 219, 0.15);
    color: #85c1e9;
    border-color: rgba(52, 152, 219, 0.2);
}

/* Fix border colors on cards in dark mode */
[data-theme="dark"] .border-primary { border-color: rgba(52, 152, 219, 0.3) !important; }
[data-theme="dark"] .border-success { border-color: rgba(46, 204, 113, 0.3) !important; }
[data-theme="dark"] .border-info { border-color: rgba(23, 162, 184, 0.3) !important; }
[data-theme="dark"] .border-warning { border-color: rgba(241, 196, 15, 0.3) !important; }
[data-theme="dark"] .border-danger { border-color: rgba(231, 76, 60, 0.3) !important; }

/* Modal and Input Overrides */
[data-theme="dark"] .modal-content {
    background-color: var(--card-bg);
    border-color: var(--border-color);
}

[data-theme="dark"] .modal-header,
[data-theme="dark"] .modal-footer {
    border-color: var(--border-color);
}

[data-theme="dark"] .close {
    filter: invert(1) grayscale(100%) brightness(200%);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}
.sidebar {
    min-height: 100vh;
    max-height: 100vh;
    background: var(--sidebar-bg);
    padding: 0;
    position: fixed;
    width: 250px;
    transition: background 0.3s ease;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}
.sidebar-content {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding-bottom: 20px;
    min-height: 0;
}
.sidebar-content::-webkit-scrollbar {
    width: 6px;
}
.sidebar-content::-webkit-scrollbar-track {
    background: rgba(255,255,255,0.05);
}
.sidebar-content::-webkit-scrollbar-thumb {
    background: rgba(255,255,255,0.2);
    border-radius: 3px;
}
.sidebar-content::-webkit-scrollbar-thumb:hover {
    background: rgba(255,255,255,0.3);
}
.sidebar .nav-link {
    color: var(--sidebar-text);
    padding: 12px 20px;
    margin: 5px 10px;
    border-radius: 8px;
    transition: all 0.3s;
}
.sidebar .nav-link:hover, .sidebar .nav-link.active {
    color: white;
    background-color: var(--sidebar-hover);
}
.sidebar .nav-link i {
    margin-right: 10px;
    width: 20px;
}
.sidebar .nav-category {
    color: rgba(255,255,255,0.7);
    padding: 12px 20px;
    margin: 10px 10px 5px 10px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    cursor: pointer;
    user-select: none;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-radius: 8px;
    transition: all 0.3s ease;
}
.sidebar .nav-category:hover {
    background-color: var(--sidebar-hover);
    color: rgba(255,255,255,0.9);
}
.sidebar .nav-category i.bi-chevron-right {
    transition: transform 0.3s ease;
    font-size: 0.7rem;
    margin-left: auto;
    margin-right: 5px;
}
.sidebar .nav-category[aria-expanded="true"] i.bi-chevron-right {
    transform: rotate(90deg);
}
.sidebar .nav-submenu {
    padding: 0;
    margin: 0;
}
.sidebar .nav-submenu .nav-link {
    padding: 10px 20px 10px 40px;
    font-size: 0.9rem;
}
.content {
    margin-left: 250px;
    padding: 30px;
    transition: opacity 0.3s ease;
}
.content.loading {
    opacity: 0.5;
    pointer-events: none;
}
.loading-spinner {
    position: fixed;
    top: 50%;
    left: calc(250px + 50%);
    transform: translate(-50%, -50%);
    z-index: 9999;
    display: none;
}
.loading-spinner.active {
    display: block;
}
.card {
    border: none;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
    margin-bottom: 20px;
    background-color: var(--card-bg);
    transition: background-color 0.3s ease;
}
.card-header {
    background-color: var(--card-bg);
    border-bottom: 2px solid var(--border-color);
    font-weight: 600;
    padding: 15px 20px;
    color: var(--text-color);
    transition: all 0.3s ease;
}
.metric-card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    height: 100%;
    border: 1px solid rgba(0,0,0,0.05);
    position: relative;
    overflow: hidden;
}
.metric-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.12);
}
.metric-card .value {
    font-size: 2rem;
    font-weight: bold;
    color: var(--text-color);
    margin-bottom: 8px;
    line-height: 1.2;
}
.metric-card .label {
    color: var(--text-muted);
    font-size: 0.85rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}
.metric-icon {
    width: 56px;
    height: 56px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.75rem;
    flex-shrink: 0;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}
.metric-icon.bg-primary { 
    background: linear-gradient(135deg, #3498db 0%, #2980b9 100%);
}
.metric-icon.bg-warning { 
    background: linear-gradient(135deg, #f39c12 0%, #e67e22 100%);
}
.metric-icon.bg-info { 
    background: linear-gradient(135deg, #17a2b8 0%, #138496 100%);
}
.metric-icon.bg-success { 
    background: linear-gradient(135deg, #27ae60 0%, #229954 100%);
}

/* Small decorative box effect */
.metric-card::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 100px;
    height: 100px;
    background: linear-gradient(135deg, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0) 100%);
    border-radius: 0 0 0 100%;
    pointer-events: none;
}
.btn-primary {
    background-color: var(--secondary-color);
    border-color: var(--secondary-color);
}
.btn-primary:hover {
    background-color: #2980b9;
    border-color: #2980b9;
}
.user-info {
    padding: 20px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.user-info-text h6 {
    margin: 0;
    font-weight: 600;
}
.user-info-text small {
    opacity: 0.8;
}
.theme-toggle {
    cursor: pointer;
    font-size: 1.2rem;
    padding: 5px 10px;
    border-radius: 6px;
    transition: all 0.3s ease;
    background: rgba(255,255,255,0.1);
    border: none;
    color: white;
}
.theme-toggle:hover {
    background: rgba(255,255,255,0.2);
}
table.table {
    background: var(--card-bg);
    color: var(--text-color);
    transition: all 0.3s ease;
}
.table thead {
    border-bottom: 2px solid var(--border-color);
}
.table td, .table th {
    border-color: var(--border-color);
}
.table-hover tbody tr:hover {
    background-color: var(--sidebar-hover);
}
.badge {
    padding: 6px 12px;
    border-radius: 6px;
}
.alert {
    border-radius: 10px;
    border: none;
}
/* Modern Page Header */
.page-header {
    margin-bottom: 30px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 16px;
    padding: 30px 35px;
    color: white;
    box-shadow: 0 8px 24px rgba(102, 126, 234, 0.25);
    position: relative;
    overflow: hidden;
    transition: all 0.3s ease;
}
.page-header::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    animation: rotate 20s linear infinite;
    pointer-events: none;
}
.page-header:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 32px rgba(102, 126, 234, 0.35);
}
.page-header h1 {
    color: white;
    font-weight: 700;
    margin-bottom: 8px;
    font-size: 2rem;
    display: flex;
    align-items: center;
    gap: 15px;
    position: relative;
    z-index: 1;
}
.page-header h1 i {
    font-size: 2.2rem;
    opacity: 0.95;
    filter: drop-shadow(2px 2px 4px rgba(0,0,0,0.2));
}
.page-header p {
    color: rgba(255,255,255,0.9);
    margin: 0;
    font-size: 1.05rem;
    font-weight: 400;
    padding-left: 52px;
    position: relative;
    z-index: 1;
}

/* Dark Mode Page Header */
[data-theme="dark"] .page-header {
    background: linear-gradient(135deg, #4a5fc1 0%, #5a3d7a 100%);
    box-shadow: 0 8px 24px rgba(74, 95, 193, 0.3);
}
[data-theme="dark"] .page-header:hover {
    box-shadow: 0 12px 32px rgba(74, 95, 193, 0.4);
}
.form-control, .form-select {
    border-radius: 8px;
    border: 1px solid var(--border-color);
    padding: 10px 15px;
    background-color: var(--card-bg);
    color: var(--text-color);
    transition: all 0.3s ease;
}
.form-control:focus, .form-select:focus {
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 0.2rem rgba(52, 152, 219, 0.25);
    background-color: var(--card-bg);
    color: var(--text-color);
}
.form-control::placeholder {
    color: var(--text-muted);
}
.btn {
    border-radius: 8px;
    padding: 10px 20px;
    font-weight: 500;
}
/* Dropdown Menu Dark Mode */
[data-theme="dark"] .dropdown-menu {
    background-color: var(--card-bg);
    border-color: var(--border-color);
    color: var(--text-color);
}
[data-theme="dark"] .dropdown-item {
    color: var(--text-color);
}
[data-theme="dark"] .dropdown-item:hover,
[data-theme="dark"] .dropdown-item:focus {
    background-color: var(--sidebar-hover);
    color: white;
}
[data-theme="dark"] .dropdown-divider {
    border-top-color: var(--border-color);
}

/* Table Dark Mode Overrides */
[data-theme="dark"] .table-striped > tbody > tr:nth-of-type(odd) > * {
    background-color: rgba(255, 255, 255, 0.03);
    color: var(--text-color);
}
[data-theme="dark"] .table-hover > tbody > tr:hover > * {
    background-color: rgba(255, 255, 255, 0.05); 
    color: var(--text-color);
}
[data-theme="dark"] .table {
    border-color: var(--border-color);
    color: var(--text-color);
}

/* Form Check/Radio */
[data-theme="dark"] .form-check-input {
    background-color: var(--card-bg);
    border-color: var(--text-muted);
}
[data-theme="dark"] .form-check-input:checked {
    background-color: var(--secondary-color);
    border-color: var(--secondary-color);
}

/* Scrollbars */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-color); 
}
::-webkit-scrollbar-thumb {
    background: #ccc; 
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: #bbb; 
}
[data-theme="dark"] ::-webkit-scrollbar-track {
    background: #2d2d2d; 
}
[data-theme="dark"] ::-webkit-scrollbar-thumb {
    background: #666; 
}
[data-theme="dark"] ::-webkit-scrollbar-thumb:hover {
    background: #888; 
}

/* Input Autofill Fix for Dark Mode */
[data-theme="dark"] input:-webkit-autofill,
[data-theme="dark"] input:-webkit-autofill:hover, 
[data-theme="dark"] input:-webkit-autofill:focus, 
[data-theme="dark"] input:-webkit-autofill:active {
    -webkit-box-shadow: 0 0 0 30px var(--card-bg) inset !important;
    -webkit-text-fill-color: var(--text-color) !important;
    transition: background-color 5000s ease-in-out 0s;
}
/* User Management Utilities */
.avatar-sm {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

[data-theme="dark"] .avatar-sm {
    background-color: rgba(255, 255, 255, 0.05) !important;
}

.table thead th {
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted);
}

.modal-header .btn-close-white {
    filter: invert(1) grayscale(100%) brightness(200%);
}

[data-theme="dark"] .modal-header .btn-close-white {
    filter: none;
}