:root {
    color-scheme: light;
    --sidebar-bg: #121926;
    --sidebar-color: #e6e9f2;
    --accent: #0d6efd;
    --accent-hover: #0b5ed7;
    --accent-dark: #0a58ca;
    --surface: #ffffff;
    --muted: #6c757d;
    --success: #198754;
    --danger: #dc3545;
    --warning: #ffc107;
    --info: #0dcaf0;
}

* {
    box-sizing: border-box;
}

html, body {
    height: 100%;
}

body {
    background: linear-gradient(135deg, #f4f7fb 0%, #eef2f5 100%);
    color: #343a40;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

.sidebar {
    min-height: 100vh;
    background: linear-gradient(180deg, var(--sidebar-bg) 0%, #0f1419 100%);
    box-shadow: 2px 0 8px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
}

.sidebar a {
    color: var(--sidebar-color);
}

.sidebar .nav-link {
    border-radius: 0.5rem;
    margin-bottom: 0.25rem;
    transition: all 0.2s ease;
    padding: 0.75rem 1rem;
}

.sidebar .nav-link:hover {
    background: rgba(13, 110, 253, 0.2);
    color: #fff;
    padding-left: 1.25rem;
}

.sidebar .nav-link.active {
    background: linear-gradient(90deg, var(--accent) 0%, var(--accent-hover) 100%);
    color: #fff;
    font-weight: 600;
    box-shadow: 0 2px 8px rgba(13, 110, 253, 0.4);
}

.navbar {
    background: linear-gradient(90deg, #fff 0%, #f8fbff 100%);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    border-bottom: 1px solid #e9ecef;
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar .btn-outline-secondary {
    border-color: #dee2e6;
    color: #6c757d;
}

.navbar .btn-outline-secondary:hover {
    background: #f8f9fa;
    border-color: #adb5bd;
    color: #495057;
}

.card {
    border-radius: 1rem;
    border: 1px solid #e9ecef;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.card:hover {
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
    transform: translateY(-2px);
}

.card-header {
    background: linear-gradient(90deg, #f8fbff 0%, #f0f4f8 100%);
    border-bottom: 2px solid #e9ecef;
}

.table {
    background: var(--surface);
    border-collapse: collapse;
}

.table thead th {
    background: linear-gradient(90deg, #f8fbff 0%, #f0f4f8 100%);
    border-bottom: 2px solid #dee2e6;
    font-weight: 600;
    color: #495057;
    text-transform: uppercase;
    font-size: 0.85rem;
    letter-spacing: 0.5px;
    padding: 1rem 0.75rem;
}

.table tbody tr {
    border-bottom: 1px solid #e9ecef;
    transition: all 0.2s ease;
}

.table tbody tr:hover {
    background: #f8fbff;
}

.table tbody td {
    padding: 0.75rem;
    vertical-align: middle;
}

.btn-primary {
    background: linear-gradient(90deg, var(--accent) 0%, var(--accent-hover) 100%);
    border: none;
    box-shadow: 0 2px 8px rgba(13, 110, 253, 0.3);
    transition: all 0.2s ease;
    font-weight: 500;
}

.btn-primary:hover {
    background: linear-gradient(90deg, var(--accent-hover) 0%, var(--accent-dark) 100%);
    box-shadow: 0 4px 12px rgba(13, 110, 253, 0.4);
    transform: translateY(-1px);
}

.btn-outline-primary {
    color: var(--accent);
    border-color: var(--accent);
    transition: all 0.2s ease;
}

.btn-outline-primary:hover {
    background: var(--accent);
    border-color: var(--accent);
    transform: translateY(-1px);
}

.btn-success {
    background: linear-gradient(90deg, var(--success) 0%, #15a24f 100%);
    border: none;
}

.btn-success:hover {
    background: linear-gradient(90deg, #15a24f 0%, #118c3d 100%);
}

.btn-danger {
    background: linear-gradient(90deg, var(--danger) 0%, #bb2d3b 100%);
    border: none;
}

.btn-danger:hover {
    background: linear-gradient(90deg, #bb2d3b 0%, #a02622 100%);
}

.form-control, .form-select {
    border: 1px solid #dee2e6;
    border-radius: 0.5rem;
    transition: all 0.2s ease;
}

.form-control:focus, .form-select:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 0.2rem rgba(13, 110, 253, 0.15);
}

.form-label {
    font-weight: 600;
    color: #495057;
    margin-bottom: 0.5rem;
}

.alert {
    border-radius: 0.75rem;
    border: none;
    padding: 1rem 1.25rem;
    font-weight: 500;
}

.alert-success {
    background: linear-gradient(90deg, rgba(25, 135, 84, 0.1) 0%, rgba(25, 135, 84, 0.05) 100%);
    color: #155724;
    border-left: 4px solid var(--success);
}

.alert-danger {
    background: linear-gradient(90deg, rgba(220, 53, 69, 0.1) 0%, rgba(220, 53, 69, 0.05) 100%);
    color: #721c24;
    border-left: 4px solid var(--danger);
}

.alert-info {
    background: linear-gradient(90deg, rgba(13, 202, 240, 0.1) 0%, rgba(13, 202, 240, 0.05) 100%);
    color: #0c5460;
    border-left: 4px solid var(--info);
}

.alert .btn-close {
    opacity: 0.5;
    transition: opacity 0.2s ease;
}

.alert .btn-close:hover {
    opacity: 0.8;
}

.badge {
    padding: 0.5rem 0.75rem;
    font-weight: 500;
    border-radius: 0.5rem;
}

.badge.bg-info {
    background: linear-gradient(90deg, var(--info) 0%, #08bdd4 100%) !important;
}

.list-group-item {
    border: 1px solid #e9ecef;
    transition: all 0.2s ease;
    padding: 0.75rem 1rem;
}

.list-group-item:hover {
    background: #f8fbff;
}

.dropdown-menu {
    border: 1px solid #e9ecef;
    border-radius: 0.5rem;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
}

.dropdown-item {
    padding: 0.75rem 1rem;
    transition: all 0.2s ease;
}

.dropdown-item:hover {
    background: #f8fbff;
    color: var(--accent);
}

.page-link {
    color: var(--accent);
    border-color: #dee2e6;
}

.page-link:hover {
    background: #f8fbff;
    border-color: var(--accent);
    color: var(--accent-hover);
}

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

/* DataTables customization */
.dataTables_wrapper .dataTables_paginate .paginate_button {
    border-radius: 0.25rem;
    margin: 0 2px;
    transition: all 0.2s ease;
}

.dataTables_wrapper .dataTables_paginate .paginate_button.current {
    background: linear-gradient(90deg, var(--accent) 0%, var(--accent-hover) 100%);
    border-color: var(--accent);
}

.dataTables_wrapper .dataTables_filter input {
    border-radius: 0.5rem;
    border: 1px solid #dee2e6;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        z-index: 1000;
        max-width: 260px;
    }

    body {
        overflow-x: hidden;
    }

    .card {
        margin-bottom: 1rem;
    }

    .table-responsive {
        border-radius: 0.5rem;
    }
}

/* Print styles */
@media print {
    .sidebar, .navbar, .btn {
        display: none;
    }

    .card {
        page-break-inside: avoid;
        border: 1px solid #ddd;
        box-shadow: none;
    }

    body {
        background: white;
    }
}