:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --accent: #ec4899;
    --sidebar-width: 250px;
    --navbar-height: 56px;
}

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background-color: #f1f5f9;
    min-height: 100vh;
}

/* Login Page */
.login-page {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    min-height: 100vh;
}

.brand-icon {
    width: 72px;
    height: 72px;
    background: rgba(255,255,255,0.15);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 32px;
    color: #fff;
    backdrop-filter: blur(10px);
    border: 2px solid rgba(255,255,255,0.3);
}

/* Navbar */
.main-navbar {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    box-shadow: 0 2px 12px rgba(99,102,241,0.3);
    z-index: 1030;
}

.main-navbar .navbar-brand {
    font-size: 1.25rem;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    min-height: calc(100vh - var(--navbar-height));
    background: #fff;
    border-right: 1px solid #e2e8f0;
    box-shadow: 2px 0 8px rgba(0,0,0,0.04);
    transition: transform 0.3s ease;
    flex-shrink: 0;
}

.sidebar .nav-link {
    color: #64748b;
    padding: 0.75rem 1.25rem;
    font-weight: 500;
    border-left: 3px solid transparent;
    transition: all 0.2s;
}

.sidebar .nav-link:hover {
    color: var(--primary);
    background: #f1f5f9;
    border-left-color: var(--primary);
}

.sidebar .nav-link.active {
    color: var(--primary);
    background: rgba(99,102,241,0.08);
    border-left-color: var(--primary);
    font-weight: 600;
}

.sidebar .nav-link i {
    font-size: 1.1rem;
}

/* Main Content */
.main-content {
    min-height: calc(100vh - var(--navbar-height));
    overflow-x: hidden;
}

/* Stats Cards */
.stat-card {
    border-radius: 12px;
    transition: transform 0.2s;
}

.stat-card:hover {
    transform: translateY(-2px);
}

.stat-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
}

/* Cards */
.card {
    border-radius: 12px;
}

.card-header {
    border-bottom: 1px solid #f1f5f9;
    padding: 1rem 1.25rem;
}

/* Tables */
.table th {
    font-weight: 600;
    font-size: 0.85rem;
    text-transform: uppercase;
    color: #64748b;
    letter-spacing: 0.03em;
}

.table td {
    vertical-align: middle;
}

/* Badges */
.badge {
    font-weight: 500;
    padding: 0.4em 0.7em;
    border-radius: 6px;
}

/* Buttons */
.btn-primary {
    background: var(--primary);
    border-color: var(--primary);
}

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

/* FullCalendar customization */
.fc .fc-button-primary {
    background: var(--primary) !important;
    border-color: var(--primary) !important;
}

.fc .fc-button-primary:not(:disabled).fc-button-active,
.fc .fc-button-primary:not(:disabled):active {
    background: var(--primary-dark) !important;
    border-color: var(--primary-dark) !important;
}

.fc .fc-daygrid-day-number {
    color: #334155;
}

.fc .fc-event {
    border-radius: 4px;
    padding: 2px 4px;
    font-size: 0.8rem;
    cursor: pointer;
}

/* DataTables */
.dataTables_wrapper .dataTables_filter input {
    border-radius: 8px;
    border: 1px solid #e2e8f0;
    padding: 0.375rem 0.75rem;
}

/* Responsive */
@media (max-width: 991.98px) {
    .sidebar {
        position: fixed;
        top: var(--navbar-height);
        left: 0;
        transform: translateX(-100%);
        z-index: 1020;
        height: calc(100vh - var(--navbar-height));
        overflow-y: auto;
    }

    .sidebar.show {
        transform: translateX(0);
        box-shadow: 4px 0 16px rgba(0,0,0,0.1);
    }

    .main-content {
        width: 100%;
    }
}

@media (max-width: 575.98px) {
    .stat-icon {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }

    .container-fluid {
        padding: 1rem !important;
    }

    h4 {
        font-size: 1.1rem;
    }
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: #f1f5f9;
}

::-webkit-scrollbar-thumb {
    background: #cbd5e1;
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: #94a3b8;
}

/* Modal */
.modal-header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    color: #fff;
    border-radius: 12px 12px 0 0;
}

.modal-header .btn-close {
    filter: brightness(0) invert(1);
}

.modal-content {
    border-radius: 12px;
    border: none;
}

/* SweetAlert2 customization */
.swal2-confirm {
    background: var(--primary) !important;
}

/* Dark Mode Toggle */
.theme-toggle {
    background: rgba(255,255,255,0.15);
    border: 1px solid rgba(255,255,255,0.25);
    color: #fff;
    width: 36px;
    height: 36px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 1.1rem;
    transition: all 0.2s;
    backdrop-filter: blur(4px);
}
.theme-toggle:hover {
    background: rgba(255,255,255,0.25);
}

/* ========== DARK MODE ========== */
[data-theme="dark"] body,
body.dark {
    background-color: #0f172a;
    color: #e2e8f0;
}

body.dark .sidebar {
    background: #1e293b;
    border-right-color: #334155;
}

body.dark .sidebar .nav-link {
    color: #94a3b8;
}

body.dark .sidebar .nav-link:hover {
    color: var(--primary);
    background: #334155;
}

body.dark .sidebar .nav-link.active {
    color: #a5b4fc;
    background: rgba(99,102,241,0.15);
}

body.dark .card {
    background: #1e293b;
    border-color: #334155;
}

body.dark .card-header {
    border-bottom-color: #334155;
    background: #1e293b;
}

body.dark .stat-card {
    background: #1e293b;
    border-color: #334155;
}

body.dark .table,
body.dark .table thead,
body.dark .table tbody,
body.dark .table tr,
body.dark .table td,
body.dark .table th,
body.dark table.dataTable thead th,
body.dark table.dataTable tbody td {
    color: #e2e8f0 !important;
    border-color: #334155 !important;
    --bs-table-color: #e2e8f0;
    --bs-table-bg: transparent;
    --bs-table-border-color: #334155;
    --bs-table-striped-color: #e2e8f0;
    --bs-table-hover-color: #f1f5f9;
    --bs-table-hover-bg: rgba(51,65,85,0.5);
}

body.dark .table th {
    color: #94a3b8 !important;
}

body.dark .table-hover tbody tr:hover,
body.dark .table-hover tbody tr:hover td {
    background: #334155 !important;
    color: #f1f5f9 !important;
}

body.dark .table-striped>tbody>tr:nth-of-type(odd)>* {
    color: #e2e8f0 !important;
    --bs-table-bg-type: rgba(51,65,85,0.3);
    background-color: rgba(51,65,85,0.3) !important;
}

body.dark .table-striped>tbody>tr:nth-of-type(even)>* {
    color: #e2e8f0 !important;
    background-color: transparent !important;
}

body.dark .form-control,
body.dark .form-select {
    background: #334155;
    border-color: #475569;
    color: #e2e8f0;
}

body.dark .form-control::placeholder {
    color: #64748b;
}

body.dark .form-control:focus,
body.dark .form-select:focus {
    background: #3b4c63;
    border-color: var(--primary);
    color: #f1f5f9;
}

body.dark .input-group-text {
    background: #475569;
    border-color: #475569;
    color: #94a3b8;
}

body.dark .modal-content {
    background: #1e293b;
    color: #e2e8f0;
}

body.dark .modal-body {
    background: #1e293b;
}

body.dark .modal-footer {
    border-top-color: #334155;
    background: #1e293b;
}

body.dark .btn-secondary {
    background: #475569;
    border-color: #475569;
    color: #e2e8f0;
}

body.dark .btn-outline-secondary {
    border-color: #475569;
    color: #94a3b8;
}

body.dark .btn-outline-secondary:hover {
    background: #475569;
    color: #e2e8f0;
}

body.dark .btn-light {
    background: #334155;
    border-color: #475569;
    color: #e2e8f0;
}

body.dark .dropdown-menu {
    background: #1e293b;
    border-color: #334155;
}

body.dark .dropdown-item {
    color: #e2e8f0;
}

body.dark .dropdown-item:hover {
    background: #334155;
    color: #f1f5f9;
}

body.dark .dropdown-divider {
    border-color: #334155;
}

body.dark .text-muted {
    color: #64748b !important;
}

body.dark h4, body.dark h5, body.dark h6,
body.dark .fw-bold, body.dark .fw-semibold {
    color: #f1f5f9;
}

body.dark .border {
    border-color: #334155 !important;
}

body.dark .bg-light {
    background-color: #334155 !important;
}

body.dark .bg-white {
    background-color: #1e293b !important;
}

/* Dark FullCalendar */
body.dark .fc .fc-daygrid-day-number {
    color: #e2e8f0;
}

body.dark .fc .fc-col-header-cell-cushion {
    color: #94a3b8;
}

body.dark .fc td, body.dark .fc th {
    border-color: #334155;
}

body.dark .fc .fc-scrollgrid {
    border-color: #334155;
}

body.dark .fc .fc-daygrid-day.fc-day-today {
    background: rgba(99,102,241,0.15);
}

body.dark .fc .fc-toolbar-title {
    color: #f1f5f9;
}

body.dark .fc .fc-button-primary:disabled {
    background: #475569 !important;
    border-color: #475569 !important;
}

/* Dark DataTables */
body.dark .dataTables_wrapper .dataTables_filter input {
    background: #334155;
    border-color: #475569;
    color: #e2e8f0;
}

body.dark .dataTables_wrapper .dataTables_length select {
    background: #334155;
    border-color: #475569;
    color: #e2e8f0;
}

body.dark .dataTables_wrapper .dataTables_info,
body.dark .dataTables_wrapper .dataTables_length label,
body.dark .dataTables_wrapper .dataTables_filter label {
    color: #94a3b8;
}

body.dark .dataTables_wrapper .dataTables_paginate .paginate_button {
    color: #94a3b8 !important;
}

body.dark .dataTables_wrapper .dataTables_paginate .paginate_button.current {
    background: var(--primary) !important;
    border-color: var(--primary) !important;
    color: #fff !important;
}

body.dark .dataTables_wrapper .dataTables_paginate .paginate_button:hover {
    background: #334155 !important;
    border-color: #475569 !important;
    color: #f1f5f9 !important;
}

/* Dark Scrollbar */
body.dark ::-webkit-scrollbar-track {
    background: #1e293b;
}

body.dark ::-webkit-scrollbar-thumb {
    background: #475569;
}

body.dark ::-webkit-scrollbar-thumb:hover {
    background: #64748b;
}

/* Dark page-link (pagination) */
body.dark .page-link {
    background: #334155;
    border-color: #475569;
    color: #e2e8f0;
}

body.dark .page-item.active .page-link {
    background: var(--primary);
    border-color: var(--primary);
}

/* Dark Charts */
body.dark .chart-container canvas {
    filter: brightness(0.95);
}

/* Dark Alert */
body.dark .alert-info {
    background: rgba(59,130,246,0.15);
    border-color: rgba(59,130,246,0.3);
    color: #93c5fd;
}

body.dark .alert-warning {
    background: rgba(245,158,11,0.15);
    border-color: rgba(245,158,11,0.3);
    color: #fcd34d;
}

/* Dark list-group */
body.dark .list-group-item {
    background: #1e293b;
    border-color: #334155;
    color: #e2e8f0;
}

/* Dark Login Page */
body.dark.login-page {
    background: linear-gradient(135deg, #1e1b4b 0%, #831843 100%);
}

body.dark .card {
    color: #e2e8f0;
}

body.dark .card-title {
    color: #f1f5f9;
}

body.dark .form-check-label {
    color: #94a3b8;
}

body.dark a:not(.btn):not(.nav-link):not(.navbar-brand):not(.dropdown-item) {
    color: #a5b4fc;
}

/* Transition for smooth theme switch */
body, .sidebar, .card, .table, .form-control, .form-select,
.modal-content, .dropdown-menu, .btn, .list-group-item {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}