:root {
    --bg-main: #f8fafc;
    --bg-card: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --accent-dark: #0f172a;
    --accent-hover: #1e293b;
    --accent-primary: #2563eb;
    --success: #10b981;
    --danger: #ef4444;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.05);
    --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.06);
    --shadow-lg: 0 10px 25px rgba(15, 23, 42, 0.08);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    -webkit-font-smoothing: antialiased;
}

body {
    background-color: var(--bg-main);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

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

.admin-sidebar {
    width: 260px;
    background: #ffffff;
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 24px 16px;
    flex-shrink: 0;
}

.sidebar-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 0 12px 24px 12px;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 24px;
}

.brand-icon-box {
    width: 40px;
    height: 40px;
    background: var(--accent-dark);
    color: #ffffff;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.brand-title {
    font-size: 1.15rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

.brand-badge {
    font-size: 0.7rem;
    font-weight: 700;
    background: #f1f5f9;
    color: #475569;
    padding: 2px 8px;
    border-radius: 999px;
    margin-left: 4px;
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 6px;
    flex: 1;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 14px;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.92rem;
    font-weight: 600;
    transition: all 0.15s ease;
}

.nav-link:hover {
    background: #f1f5f9;
    color: var(--text-primary);
}

.nav-link.active {
    background: var(--accent-dark);
    color: #ffffff;
}

.sidebar-footer {
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
}

.admin-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
}

.admin-header {
    height: 70px;
    background: #ffffff;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 32px;
}

.header-title-box h1 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.header-user {
    display: flex;
    align-items: center;
    gap: 14px;
}

.user-avatar {
    width: 38px;
    height: 38px;
    border-radius: 50%;
    background: #e2e8f0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: #334155;
    font-size: 0.85rem;
}

.admin-content {
    padding: 32px;
    flex: 1;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
    margin-bottom: 32px;
}

.stat-card {
    background: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.stat-info h3 {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    margin-bottom: 6px;
}

.stat-info .stat-value {
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--text-primary);
}

.stat-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    background: #f8fafc;
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
}

.content-card {
    background: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

.card-header-bar {
    padding: 20px 24px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.card-title {
    font-size: 1.1rem;
    font-weight: 700;
}

.btn-primary {
    background: var(--accent-dark);
    color: #ffffff;
    border: none;
    border-radius: var(--radius-md);
    padding: 10px 18px;
    font-weight: 600;
    font-size: 0.88rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    transition: background 0.15s ease;
}

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

.btn-secondary {
    background: #ffffff;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 9px 16px;
    font-weight: 600;
    font-size: 0.88rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    transition: background 0.15s ease;
}

.btn-secondary:hover {
    background: #f8fafc;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
}

.data-table th {
    background: #f8fafc;
    padding: 14px 20px;
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-bottom: 1px solid var(--border-color);
}

.data-table td {
    padding: 16px 20px;
    font-size: 0.88rem;
    border-bottom: 1px solid var(--border-color);
    vertical-align: middle;
}

.data-table tr:hover {
    background: #fafafa;
}

.badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 10px;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 700;
}

.badge-success {
    background: #ecfdf5;
    color: #059669;
}

.badge-danger {
    background: #fef2f2;
    color: #dc2626;
}

.key-code {
    background: #f1f5f9;
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    font-family: monospace;
    font-size: 0.8rem;
    font-weight: 600;
    color: #334155;
    border: 1px solid #e2e8f0;
    user-select: all;
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    padding: 24px;
}

.form-full {
    grid-column: span 2;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-label {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.form-control {
    height: 44px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 0 14px;
    font-size: 0.9rem;
    outline: none;
    transition: border-color 0.15s ease;
}

.form-control:focus {
    border-color: var(--accent-dark);
}

.form-textarea {
    height: 80px;
    padding: 12px 14px;
    resize: vertical;
}

.login-wrapper {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #f8fafc;
    padding: 20px;
}

.login-card {
    width: 100%;
    max-width: 420px;
    background: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    padding: 40px;
}

.login-header {
    text-align: center;
    margin-bottom: 28px;
}

.login-icon-box {
    width: 56px;
    height: 56px;
    background: var(--accent-dark);
    color: #ffffff;
    border-radius: var(--radius-md);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
}