:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --text-primary: #212529;
    --text-secondary: #6c757d;
    --text-muted: #adb5bd;
    --border-color: #dee2e6;
    --accent-primary: #4a90e2;
    --accent-success: #28a745;
    --accent-danger: #dc3545;
    --accent-warning: #ffc107;
    --accent-info: #17a2b8;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 8px rgba(0,0,0,0.15);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --transition-fast: 0.2s ease;
}

[data-theme="dark"] {
    --bg-primary: #1a1d23;
    --bg-secondary: #252930;
    --bg-tertiary: #2f3439;
    --text-primary: #e9ecef;
    --text-secondary: #adb5bd;
    --text-muted: #6c757d;
    --border-color: #3a3f47;
    --accent-primary: #5a9ff5;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
    width: 100%;
}

/* Navbar */
.navbar {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    box-shadow: var(--shadow-sm);
}

.navbar-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

.navbar-brand .logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-primary);
    text-decoration: none;
}

.navbar-menu {
    display: flex;
    gap: 0.5rem;
    align-items: center;
    flex-wrap: wrap;
}

.navbar-user {
    display: flex;
    align-items: center;
    padding: 0.5rem 1rem;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
}

.user-welcome {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
}

.navbar-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    color: var(--text-primary);
    text-decoration: none;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.navbar-link:hover {
    background: var(--bg-secondary);
    color: var(--accent-primary);
}

.navbar-link-logout {
    color: var(--accent-danger);
}

.navbar-link-logout:hover {
    background: rgba(220, 53, 69, 0.1);
}

/* Theme toggle */
.theme-toggle {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 0.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.theme-toggle:hover {
    background: var(--bg-tertiary);
}

.theme-toggle svg {
    width: 20px;
    height: 20px;
}

.icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }

/* Main content */
.main-content {
    flex: 1;
    padding: 2rem 0;
}

/* Cards */
.card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-sm);
}

.card-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

/* Stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin: 1.5rem 0;
}

.stat-card {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: var(--radius-md);
    text-align: center;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-primary);
    display: block;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
}

.form-input, .form-select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all var(--transition-fast);
}

.form-input:focus, .form-select:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
    background: #3a7bc8;
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--bg-tertiary);
}

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

.btn-success:hover:not(:disabled) {
    background: #218838;
}

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

.btn-danger:hover:not(:disabled) {
    background: #c82333;
}

.btn-warning {
    background: var(--accent-warning);
    color: #212529;
}

.btn-warning:hover:not(:disabled) {
    background: #e0a800;
}

.btn-info {
    background: var(--accent-info);
    color: white;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

/* Tables */
.table-responsive {
    overflow-x: auto;
}

.table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

.table th, .table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    background: var(--bg-secondary);
    font-weight: 600;
    color: var(--text-primary);
}

.table tr:hover {
    background: var(--bg-secondary);
}

/* Badges */
.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.875rem;
    font-weight: 600;
}

.badge-primary {
    background: var(--accent-primary);
    color: white;
}

.badge-secondary {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
}

.badge-success {
    background: var(--accent-success);
    color: white;
}

.badge-danger {
    background: var(--accent-danger);
    color: white;
}

.badge-warning {
    background: var(--accent-warning);
    color: #212529;
}

/* Alerts */
.alert {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1rem;
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
}

.alert-icon {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
}

.alert-content {
    flex: 1;
}

.alert-success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert-error, .alert-danger {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.alert-warning {
    background: #fff3cd;
    color: #856404;
    border: 1px solid #ffeeba;
}

.alert-info {
    background: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

/* Icons */
.icon {
    width: 20px;
    height: 20px;
}

/* Utilities */
.text-bold { font-weight: 700; }
.text-muted { color: var(--text-muted); }
.text-small { font-size: 0.875rem; }
.text-center { text-align: center; }

.d-flex { display: flex; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 1.5rem; }
.mt-3 { margin-top: 1rem; }
.mt-4 { margin-top: 1.5rem; }

/* Footer */
.footer {
    background: var(--bg-primary);
    border-top: 1px solid var(--border-color);
    padding: 2rem 0;
    margin-top: auto;
}

.footer-content {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.footer-version {
    margin-top: 0.5rem;
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Responsive */
@media (max-width: 768px) {
    .navbar-content {
        flex-direction: column;
    }
    
    .navbar-menu {
        width: 100%;
        justify-content: center;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .table {
        font-size: 0.875rem;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .card {
        padding: 1rem;
    }
}