:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #dbeafe;
    --success: #16a34a;
    --success-light: #dcfce7;
    --warning: #d97706;
    --warning-light: #fef3c7;
    --danger: #dc2626;
    --danger-light: #fee2e2;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;
    --radius: 8px;
    --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1), 0 4px 6px rgba(0,0,0,0.05);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--gray-50);
    color: var(--gray-800);
    line-height: 1.6;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

.layout { display: flex; min-height: 100vh; }

.sidebar {
    width: 250px;
    background: var(--gray-900);
    color: white;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    transition: transform 0.3s;
}

.sidebar-header {
    padding: 20px;
    border-bottom: 1px solid var(--gray-700);
}

.sidebar-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #60a5fa;
}

.sidebar-header p {
    font-size: 0.75rem;
    color: var(--gray-400);
}

.sidebar-nav { padding: 10px 0; }

.sidebar-nav a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 20px;
    color: var(--gray-300);
    font-size: 0.9rem;
    transition: all 0.2s;
    border-left: 3px solid transparent;
}

.sidebar-nav a:hover {
    background: var(--gray-800);
    color: white;
    text-decoration: none;
}

.sidebar-nav a.active {
    background: var(--gray-800);
    color: white;
    border-left-color: var(--primary);
}

.sidebar-nav a svg { width: 20px; height: 20px; }

.main-content {
    flex: 1;
    margin-left: 250px;
    padding: 20px 30px;
}

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.page-header h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--gray-900);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 16px;
    margin-bottom: 24px;
}

.stat-card {
    background: white;
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--primary);
}

.stat-card.success { border-left-color: var(--success); }
.stat-card.warning { border-left-color: var(--warning); }
.stat-card.danger { border-left-color: var(--danger); }

.stat-card .label {
    font-size: 0.8rem;
    color: var(--gray-500);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.stat-card .value {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-top: 4px;
}

.card {
    background: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.card-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.card-header h3 { font-size: 1rem; font-weight: 600; }
.card-body { padding: 20px; }

.table-wrapper { overflow-x: auto; }

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

th {
    text-align: left;
    padding: 10px 16px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--gray-500);
    background: var(--gray-50);
    border-bottom: 1px solid var(--gray-200);
}

td {
    padding: 12px 16px;
    font-size: 0.875rem;
    border-bottom: 1px solid var(--gray-100);
}

tr:hover { background: var(--gray-50); }

.badge {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-success { background: var(--success-light); color: var(--success); }
.badge-warning { background: var(--warning-light); color: var(--warning); }
.badge-danger { background: var(--danger-light); color: var(--danger); }
.badge-info { background: var(--primary-light); color: var(--primary); }

.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    border: none;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

.btn:hover { text-decoration: none; opacity: 0.9; }

.btn-primary { background: var(--primary); color: white; }
.btn-success { background: var(--success); color: white; }
.btn-danger { background: var(--danger); color: white; }
.btn-outline { background: white; color: var(--gray-700); border: 1px solid var(--gray-300); }
.btn-sm { padding: 4px 10px; font-size: 0.8rem; }
.btn-icon { padding: 6px; }

.form-group { margin-bottom: 16px; }
.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--gray-700);
    margin-bottom: 4px;
}

.form-control {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-size: 0.875rem;
    transition: border-color 0.2s;
    background: white;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.form-actions {
    display: flex;
    gap: 10px;
    margin-top: 20px;
}

.alert {
    padding: 12px 16px;
    border-radius: var(--radius);
    margin-bottom: 16px;
    font-size: 0.875rem;
}

.alert-success { background: var(--success-light); color: var(--success); border: 1px solid var(--success); }
.alert-danger { background: var(--danger-light); color: var(--danger); border: 1px solid var(--danger); }
.alert-warning { background: var(--warning-light); color: var(--warning); border: 1px solid var(--warning); }

.modal-overlay {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s;
}

.modal-overlay.active { opacity: 1; pointer-events: all; }

.modal {
    background: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-header {
    padding: 16px 20px;
    border-bottom: 1px solid var(--gray-200);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 { font-size: 1.1rem; font-weight: 600; }

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--gray-400);
}

.modal-body { padding: 20px; }
.modal-footer {
    padding: 16px 20px;
    border-top: 1px solid var(--gray-200);
    display: flex;
    justify-content: flex-end;
    gap: 10px;
}

.upload-zone {
    border: 2px dashed var(--gray-300);
    border-radius: var(--radius);
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
}

.upload-zone:hover {
    border-color: var(--primary);
    background: var(--primary-light);
}

.upload-zone.dragover {
    border-color: var(--primary);
    background: var(--primary-light);
}

.upload-zone p { color: var(--gray-500); }
.upload-zone .icon { font-size: 2rem; margin-bottom: 8px; }

.toolbar {
    display: flex;
    gap: 10px;
    align-items: center;
    flex-wrap: wrap;
}

.search-box {
    position: relative;
}

.search-box input {
    padding-left: 36px;
}

.search-box svg {
    position: absolute;
    left: 10px;
    top: 50%;
    transform: translateY(-50%);
    width: 16px;
    height: 16px;
    color: var(--gray-400);
}

.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary) 0%, #1e40af 100%);
    padding: 20px;
}

.auth-card {
    background: white;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    padding: 40px;
    width: 100%;
    max-width: 420px;
}

.auth-card h1 {
    text-align: center;
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 8px;
}

.auth-card .subtitle {
    text-align: center;
    color: var(--gray-500);
    margin-bottom: 30px;
}

.auth-card .btn-primary {
    width: 100%;
    padding: 10px;
    font-size: 1rem;
}

.auth-card .footer-link {
    text-align: center;
    margin-top: 20px;
    font-size: 0.875rem;
    color: var(--gray-500);
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--gray-400);
}

.empty-state .icon { font-size: 3rem; margin-bottom: 12px; }
.empty-state p { font-size: 0.9rem; }

.pagination {
    display: flex;
    justify-content: center;
    gap: 4px;
    margin-top: 20px;
}

.pagination a, .pagination span {
    padding: 6px 12px;
    border-radius: var(--radius);
    font-size: 0.875rem;
    border: 1px solid var(--gray-200);
    color: var(--gray-600);
}

.pagination a:hover { background: var(--gray-50); text-decoration: none; }
.pagination .active { background: var(--primary); color: white; border-color: var(--primary); }

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }
    .sidebar.open { transform: translateX(0); }
    .main-content { margin-left: 0; padding: 16px; }
    .stats-grid { grid-template-columns: 1fr 1fr; }
    .form-row { grid-template-columns: 1fr; }
    .page-header { flex-direction: column; gap: 10px; align-items: flex-start; }
}