:root {
    --primary-color: #0066cc;
    --secondary-color: #6b7280;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --info-color: #3b82f6;
    --light-color: #ffffff;
    --dark-color: #1f2937;
    --border-color: #e5e7eb;
    --text-muted: #9ca3af;
    --bg-subtle: #f9fafb;
    --bg-card: #ffffff;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.05), 0 1px 2px 0 rgba(0, 0, 0, 0.03);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.03);
    --radius: 12px;
    --radius-lg: 16px;
}

* {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'SF Pro Display', Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-subtle);
    color: var(--dark-color);
    line-height: 1.5;
    font-weight: 400;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Navbar Styling */
.navbar {
    background: var(--bg-card) !important;
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    padding: 1rem 0;
    backdrop-filter: blur(20px);
}

.navbar-brand {
    font-weight: 600;
    font-size: 1.25rem;
    letter-spacing: -0.025em;
    color: var(--dark-color) !important;
}

.nav-link {
    font-weight: 400;
    margin: 0 0.25rem;
    border-radius: var(--radius);
    transition: all 0.2s ease;
    color: var(--text-muted) !important;
    padding: 0.5rem 1rem !important;
}

.nav-link:hover {
    background-color: var(--bg-subtle);
    color: var(--dark-color) !important;
}

.nav-link.active {
    background-color: var(--primary-color);
    color: white !important;
    font-weight: 500;
}

.navbar-nav .dropdown-toggle {
    color: var(--text-muted) !important;
}

.navbar-nav .dropdown-toggle:hover {
    color: var(--dark-color) !important;
}

/* Card Styling */
.card {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    background: var(--bg-card);
    transition: all 0.2s ease;
}

.card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
}

.card-header {
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    padding: 1.5rem;
    font-weight: 500;
    color: var(--dark-color);
}

.card-header h5, .card-header h6 {
    margin: 0;
    color: var(--dark-color);
    font-weight: 500;
}

.card-body {
    padding: 1.5rem;
}

/* Stat Cards */
.stat-card-primary {
    border-left: 4px solid var(--primary-color);
    background: linear-gradient(135deg, rgba(0, 102, 204, 0.05) 0%, rgba(0, 102, 204, 0.02) 100%);
}

.stat-card-danger {
    border-left: 4px solid var(--danger-color);
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.05) 0%, rgba(239, 68, 68, 0.02) 100%);
}

.stat-card-success {
    border-left: 4px solid var(--success-color);
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.05) 0%, rgba(16, 185, 129, 0.02) 100%);
}

.stat-card-warning {
    border-left: 4px solid var(--warning-color);
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.05) 0%, rgba(245, 158, 11, 0.02) 100%);
}

.stat-value {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
    letter-spacing: -0.025em;
    color: var(--dark-color);
}

.stat-label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.025em;
}

.stat-icon {
    width: 3rem;
    height: 3rem;
    border-radius: 0.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.stat-icon-primary {
    background: rgba(0, 102, 204, 0.1);
    color: var(--primary-color);
}

.stat-icon-danger {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
}

.stat-icon-success {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
}

.stat-icon-warning {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning-color);
}

/* Buttons */
.btn {
    font-weight: 500;
    border-radius: var(--radius);
    padding: 0.625rem 1.25rem;
    transition: all 0.2s ease;
    border: 1px solid transparent;
    font-size: 0.875rem;
}

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

.btn-primary:hover {
    background: #004499;
    border-color: #004499;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
    color: white;
}

.btn-outline-primary {
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
    background: transparent;
}

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

.btn-outline-secondary {
    border: 1px solid var(--border-color);
    color: var(--text-muted);
    background: transparent;
}

.btn-outline-secondary:hover {
    background: var(--bg-subtle);
    border-color: var(--secondary-color);
    color: var(--dark-color);
    transform: translateY(-1px);
}

.btn-success {
    background: var(--success-color);
    border-color: var(--success-color);
    color: white;
}

.btn-success:hover {
    background: #059669;
    border-color: #059669;
    color: white;
}

.btn-danger {
    background: var(--danger-color);
    border-color: var(--danger-color);
    color: white;
}

.btn-danger:hover {
    background: #dc2626;
    border-color: #dc2626;
    color: white;
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: 0.8rem;
}

/* Tables */
.table {
    border-collapse: separate;
    border-spacing: 0;
}

.table th {
    background-color: var(--bg-subtle);
    color: var(--dark-color);
    font-weight: 600;
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
    border-top: none;
}

.table td {
    padding: 1rem;
    border-bottom: 1px solid var(--border-color);
    vertical-align: middle;
}

.table-striped tbody tr:nth-of-type(odd) {
    background-color: rgba(248, 250, 252, 0.5);
}

.table-responsive {
    border-radius: 0.75rem;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

/* Badges */
.badge {
    font-weight: 500;
    padding: 0.375rem 0.75rem;
    border-radius: 0.5rem;
    font-size: 0.75rem;
}

.badge.bg-secondary {
    background-color: var(--secondary-color) !important;
}

.badge.bg-danger {
    background-color: var(--danger-color) !important;
}

.badge.bg-primary {
    background-color: var(--primary-color) !important;
}

/* Forms */
.form-control, .form-select {
    border: 1.5px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 0.75rem 1rem;
    font-size: 0.875rem;
    transition: all 0.2s ease;
}

.form-control:focus, .form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-label {
    font-weight: 500;
    color: var(--dark-color);
    margin-bottom: 0.5rem;
}

/* Alerts */
.alert {
    border: none;
    border-radius: 0.75rem;
    padding: 1rem 1.25rem;
    margin-bottom: 1.5rem;
}

.alert-success {
    background-color: rgba(5, 150, 105, 0.1);
    color: var(--success-color);
    border-left: 4px solid var(--success-color);
}

.alert-warning {
    background-color: rgba(217, 119, 6, 0.1);
    color: var(--warning-color);
    border-left: 4px solid var(--warning-color);
}

.alert-danger {
    background-color: rgba(220, 38, 38, 0.1);
    color: var(--danger-color);
    border-left: 4px solid var(--danger-color);
}

/* List Group */
.list-group-item {
    border: 1px solid var(--border-color);
    padding: 1rem 1.25rem;
    transition: all 0.2s ease;
}

.list-group-item:hover {
    background-color: var(--bg-subtle);
}

/* Pagination */
.pagination .page-link {
    border: 1px solid var(--border-color);
    color: var(--dark-color);
    padding: 0.5rem 0.75rem;
    margin: 0 0.125rem;
    border-radius: 0.375rem;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    color: var(--dark-color);
    font-weight: 600;
    line-height: 1.25;
    letter-spacing: -0.025em;
}

h1 { font-size: 2.25rem; font-weight: 700; }
h2 { font-size: 1.875rem; font-weight: 600; }
h3 { font-size: 1.5rem; font-weight: 600; }
h4 { font-size: 1.25rem; font-weight: 600; }
h5 { font-size: 1.125rem; font-weight: 500; }
h6 { font-size: 1rem; font-weight: 500; }

.text-muted {
    color: var(--text-muted) !important;
}

/* Spacing */
.container {
    max-width: 1200px;
}

/* Login Page */
.login-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    box-shadow: var(--shadow-lg);
}

.brand-logo {
    font-size: 3rem;
    color: var(--primary-color);
}

/* Modal */
.modal-content {
    border: none;
    border-radius: 0.75rem;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    border-bottom: 1px solid var(--border-color);
    padding: 1.5rem;
}

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    border-top: 1px solid var(--border-color);
    padding: 1.5rem;
}

/* Empty States */
.empty-state {
    text-align: center;
    padding: 3rem 1.5rem;
    color: var(--text-muted);
}

.empty-state i {
    font-size: 4rem;
    color: var(--border-color);
    margin-bottom: 1rem;
}

/* Category Stats Container */
.category-stats-container {
    max-height: 300px;
    overflow: hidden;
    padding: 0.5rem 0;
}

/* Responsive */
@media (max-width: 768px) {
    .stat-card {
        padding: 1.5rem 1rem;
        margin-bottom: 1rem;
    }

    .stat-value {
        font-size: 1.5rem;
    }

    .card-body {
        padding: 1rem;
    }

    .table-responsive {
        font-size: 0.875rem;
    }

    .category-stats-container {
        max-height: 250px;
    }
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-subtle: #0f172a;
        --dark-color: #f8fafc;
        --border-color: #334155;
        --text-muted: #94a3b8;
    }

    body {
        background-color: var(--bg-subtle);
        color: var(--dark-color);
    }

    .card {
        background-color: #1e293b;
        border-color: var(--border-color);
    }

    .card-header {
        background-color: #1e293b;
        border-color: var(--border-color);
    }
}