:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --bg-dark: #f8fafc;
    --bg-card: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --sidebar-bg: #1e293b;
    --sidebar-text: #f8fafc;
    --radius: 8px;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-main);
}

/* Admin Layout */
.admin-layout {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: 250px;
    background: var(--sidebar-bg);
    color: var(--sidebar-text);
    padding: 20px 0;
}

.sidebar-brand {
    font-size: 1.5rem;
    font-weight: 800;
    padding: 0 20px 20px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    margin-bottom: 20px;
}
.sidebar-brand a {
    color: #fff;
    text-decoration: none;
}

.sidebar-menu {
    list-style: none;
}

.sidebar-menu li a {
    display: block;
    padding: 12px 20px;
    color: var(--sidebar-text);
    text-decoration: none;
    transition: 0.3s;
}

.sidebar-menu li a:hover,
.sidebar-menu li a.active {
    background: rgba(255,255,255,0.1);
    border-left: 4px solid var(--primary);
}

.admin-content {
    flex: 1;
    padding: 30px;
    background: var(--bg-dark);
    overflow-y: auto;
}

/* Auth Layout */
.auth-layout {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background: #0f172a;
}
.auth-card {
    background: var(--bg-card);
    padding: 40px;
    border-radius: var(--radius);
    width: 100%;
    max-width: 400px;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.1);
}

/* UI Elements */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}

.page-header h1 {
    font-size: 1.8rem;
}

.card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    border: 1px solid var(--border);
    margin-bottom: 20px;
}

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

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

th, td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

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

.btn {
    display: inline-block;
    padding: 10px 20px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    text-decoration: none;
    font-weight: 500;
}

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

.btn-sm {
    padding: 5px 10px;
    font-size: 0.85rem;
}

.btn-danger {
    background: #ef4444;
}

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

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
}

.form-control {
    width: 100%;
    padding: 10px 15px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-family: inherit;
    font-size: 1rem;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
}

textarea.form-control {
    resize: vertical;
}

/* Alerts */
.alert {
    padding: 15px 20px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-weight: 500;
}
.alert.success { background: #d1fae5; color: #065f46; }
.alert.error { background: #fee2e2; color: #991b1b; }

@media (max-width: 768px) {
    .admin-layout {
        flex-direction: column;
    }
    .sidebar {
        width: 100%;
    }
}