:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --bg: #f8fafc;
    --bg-white: #ffffff;
    --text: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --success: #22c55e;
    --warning: #f59e0b;
    --danger: #ef4444;
}

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

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

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

.sidebar {
    width: 250px;
    background: var(--bg-white);
    border-right: 1px solid var(--border);
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 2rem;
    text-decoration: none;
    color: var(--text);
}

.logo img {
    width: 40px;
    height: 40px;
}

.logo span {
    font-size: 1.25rem;
    font-weight: 600;
}

.nav {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    flex: 1;
}

.nav a {
    padding: 0.75rem 1rem;
    text-decoration: none;
    color: var(--text-muted);
    border-radius: 0.5rem;
    transition: all 0.2s;
}

.nav a:hover, .nav a.active {
    background: var(--bg);
    color: var(--text);
}

.nav-bottom {
    margin-top: auto;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
}

.main {
    flex: 1;
    padding: 2rem;
    overflow-x: auto;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

h1 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
}

h2 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.card {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    border-radius: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: all 0.2s;
}

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

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

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

.btn-secondary:hover {
    background: var(--border);
}

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

.btn-danger:hover {
    opacity: 0.9;
}

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

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

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

th {
    font-weight: 600;
    color: var(--text-muted);
    font-size: 0.875rem;
}

.alert {
    padding: 1rem;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
}

.alert-success {
    background: #dcfce7;
    color: #166534;
}

.alert-warning {
    background: #fef3c7;
    color: #92400e;
}

.alert-danger {
    background: #fee2e2;
    color: #991b1b;
}

.form-group {
    margin-bottom: 1rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-input, .form-select {
    width: 100%;
    padding: 0.625rem;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    font-size: 1rem;
}

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

.badge {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    border-radius: 0.25rem;
    font-size: 0.75rem;
    font-weight: 500;
}

.badge-success {
    background: #dcfce7;
    color: #166534;
}

.badge-warning {
    background: #fef3c7;
    color: #92400e;
}

.badge-danger {
    background: #fee2e2;
    color: #991b1b;
}

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

.text-sm {
    font-size: 0.875rem;
}

.mt-2 { margin-top: 0.5rem; }
.mt-4 { margin-top: 1rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-4 { margin-bottom: 1rem; }

.flex {
    display: flex;
}

.items-center {
    align-items: center;
}

.justify-between {
    justify-content: space-between;
}

.gap-2 {
    gap: 0.5rem;
}

.gap-4 {
    gap: 1rem;
}

code {
    background: var(--bg);
    padding: 0.125rem 0.375rem;
    border-radius: 0.25rem;
    font-size: 0.875rem;
}

@media (max-width: 768px) {
    .layout {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--border);
    }

    .nav {
        flex-direction: row;
        flex-wrap: wrap;
    }
}