:root {
    --admin-sidebar-w: 260px;
    --admin-bg: #f0f2f7;
    --admin-surface: #ffffff;
    --admin-sidebar: #111827;
    --admin-sidebar-hover: #1f2937;
    --admin-sidebar-active: #2563eb;
    --admin-text: #111827;
    --admin-muted: #6b7280;
    --admin-border: #e5e7eb;
    --admin-primary: #2563eb;
    --admin-primary-dark: #1d4ed8;
    --admin-radius: 12px;
    --admin-shadow: 0 1px 3px rgba(15, 23, 42, 0.08), 0 4px 16px rgba(15, 23, 42, 0.04);
}

* { box-sizing: border-box; }

body.admin-app {
    margin: 0;
    font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
    color: var(--admin-text);
    background: var(--admin-bg);
    min-height: 100vh;
}

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

/* Sidebar */
.admin-sidebar {
    width: var(--admin-sidebar-w);
    background: var(--admin-sidebar);
    color: #e5e7eb;
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 1040;
    overflow-y: auto;
    transition: transform 0.25s ease;
}

.admin-brand {
    padding: 1.25rem 1.25rem 1rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.admin-brand a {
    color: #fff;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.05rem;
    letter-spacing: -0.02em;
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

.admin-brand-icon {
    width: 36px;
    height: 36px;
    border-radius: 10px;
    background: linear-gradient(135deg, #3b82f6, #6366f1);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    flex-shrink: 0;
}

.admin-brand-sub {
    font-size: 0.72rem;
    color: #9ca3af;
    font-weight: 400;
    margin-top: 0.25rem;
    padding-left: 2.85rem;
}

.admin-nav {
    padding: 0.75rem 0.75rem 1.5rem;
    flex: 1;
}

.admin-nav-group {
    margin-bottom: 0.5rem;
}

.admin-nav-label {
    font-size: 0.68rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: #6b7280;
    padding: 0.5rem 0.75rem 0.35rem;
    font-weight: 600;
}

.admin-nav-link {
    display: flex;
    align-items: center;
    gap: 0.55rem;
    padding: 0.55rem 0.75rem;
    border-radius: 8px;
    color: #d1d5db;
    text-decoration: none;
    font-size: 0.875rem;
    transition: background 0.15s, color 0.15s;
    margin-bottom: 2px;
}

.admin-nav-link:hover {
    background: var(--admin-sidebar-hover);
    color: #fff;
}

.admin-nav-link.active {
    background: rgba(37, 99, 235, 0.25);
    color: #93c5fd;
    font-weight: 500;
}

.admin-nav-icon {
    width: 18px;
    text-align: center;
    opacity: 0.85;
    font-size: 0.9rem;
}

.admin-sidebar-footer {
    padding: 1rem 1.25rem;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    font-size: 0.75rem;
    color: #6b7280;
}

/* Main area */
.admin-main {
    flex: 1;
    margin-left: var(--admin-sidebar-w);
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.admin-topbar {
    background: var(--admin-surface);
    border-bottom: 1px solid var(--admin-border);
    padding: 0.85rem 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    position: sticky;
    top: 0;
    z-index: 1020;
}

.admin-page-title {
    font-size: 1.15rem;
    font-weight: 600;
    margin: 0;
    flex: 1;
    letter-spacing: -0.02em;
}

.admin-menu-toggle {
    color: var(--admin-text) !important;
    padding: 0.25rem 0.5rem;
    text-decoration: none;
}

.admin-content {
    padding: 1.5rem;
    flex: 1;
}

.admin-content-fluid {
    padding: 1.5rem;
    max-width: none;
}

.admin-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.45);
    z-index: 1035;
}

/* Cards & components */
.admin-card {
    background: var(--admin-surface);
    border: 1px solid var(--admin-border);
    border-radius: var(--admin-radius);
    box-shadow: var(--admin-shadow);
    margin-bottom: 1.25rem;
}

.admin-card .card,
.admin-content .card {
    border-radius: var(--admin-radius);
    border-color: var(--admin-border);
    box-shadow: var(--admin-shadow);
}

.admin-card .card-header,
.admin-content .card-header {
    background: #f9fafb;
    border-bottom: 1px solid var(--admin-border);
    font-weight: 600;
    font-size: 0.9rem;
}

.admin-content .card-header.bg-primary,
.admin-content .card-header.bg-success,
.admin-content .card-header.bg-danger,
.admin-content .card-header.bg-warning {
    color: #fff;
}

.admin-page-header {
    margin-bottom: 1.25rem;
}

.admin-page-header h4,
.admin-page-header .page-heading {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.35rem;
}

.admin-page-header .text-muted {
    font-size: 0.85rem;
}

.admin-stat-card {
    background: var(--admin-surface);
    border: 1px solid var(--admin-border);
    border-radius: var(--admin-radius);
    padding: 1rem 1.15rem;
    box-shadow: var(--admin-shadow);
    height: 100%;
}

.admin-stat-card .stat-label {
    font-size: 0.78rem;
    color: var(--admin-muted);
    margin-bottom: 0.25rem;
}

.admin-stat-card .stat-value {
    font-size: 1.35rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

/* Code blocks */
.admin-code-block {
    background: #0f172a;
    color: #e2e8f0;
    border-radius: 8px;
    padding: 1rem 1.15rem;
    font-family: "Cascadia Code", "Consolas", monospace;
    font-size: 0.8rem;
    line-height: 1.55;
    overflow-x: auto;
    white-space: pre-wrap;
    word-break: break-all;
    margin: 0;
}

.admin-code-tabs .nav-link {
    font-size: 0.82rem;
    color: var(--admin-muted);
    border: none;
    padding: 0.4rem 0.85rem;
}

.admin-code-tabs .nav-link.active {
    color: var(--admin-primary);
    background: transparent;
    border-bottom: 2px solid var(--admin-primary);
    font-weight: 500;
}

.admin-copy-btn {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    font-size: 0.72rem;
}

.code-wrap {
    position: relative;
}

/* DNS test result */
.dns-result-box {
    background: #f8fafc;
    border: 1px solid var(--admin-border);
    border-radius: 8px;
    padding: 1rem;
    font-family: monospace;
    font-size: 0.82rem;
    min-height: 80px;
}

.dns-result-box.success { border-color: #86efac; background: #f0fdf4; }
.dns-result-box.error { border-color: #fca5a5; background: #fef2f2; }

/* Login page */
.login-page {
    min-height: 100vh;
    display: flex;
    background: #0f172a;
}

.login-brand-panel {
    flex: 1;
    display: none;
    background: linear-gradient(135deg, #1e3a8a 0%, #4f46e5 50%, #7c3aed 100%);
    padding: 3rem;
    color: #fff;
    flex-direction: column;
    justify-content: center;
}

@media (min-width: 992px) {
    .login-brand-panel { display: flex; }
}

.login-brand-panel h1 {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 1rem;
}

.login-brand-panel p {
    font-size: 1rem;
    opacity: 0.88;
    line-height: 1.7;
    max-width: 400px;
}

.login-features {
    margin-top: 2.5rem;
    list-style: none;
    padding: 0;
}

.login-features li {
    padding: 0.45rem 0;
    font-size: 0.9rem;
    opacity: 0.9;
}

.login-features li::before {
    content: "✓ ";
    color: #86efac;
    font-weight: 700;
}

.login-form-panel {
    width: 100%;
    max-width: 480px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    background: var(--admin-bg);
}

@media (min-width: 992px) {
    .login-form-panel {
        max-width: 440px;
        background: #fff;
        box-shadow: -8px 0 32px rgba(0, 0, 0, 0.15);
    }
}

.login-card {
    width: 100%;
    max-width: 360px;
}

.login-card h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.35rem;
    letter-spacing: -0.02em;
}

.login-card .subtitle {
    color: var(--admin-muted);
    font-size: 0.9rem;
    margin-bottom: 1.75rem;
}

.login-card .form-control {
    padding: 0.65rem 0.85rem;
    border-radius: 8px;
}

.login-card .btn-primary {
    padding: 0.65rem;
    border-radius: 8px;
    background: var(--admin-primary);
    border-color: var(--admin-primary);
    font-weight: 600;
}

.login-card .btn-primary:hover {
    background: var(--admin-primary-dark);
    border-color: var(--admin-primary-dark);
}

/* Responsive */
@media (max-width: 991.98px) {
    .admin-sidebar {
        transform: translateX(-100%);
    }
    body.sidebar-open .admin-sidebar {
        transform: translateX(0);
    }
    body.sidebar-open .admin-overlay {
        display: block;
    }
    .admin-main {
        margin-left: 0;
    }
}

/* Utility overrides */
.admin-content .btn-primary {
    background: var(--admin-primary);
    border-color: var(--admin-primary);
}

.admin-content .btn-primary:hover {
    background: var(--admin-primary-dark);
    border-color: var(--admin-primary-dark);
}

.admin-content .table {
    font-size: 0.875rem;
}

.admin-content .alert {
    border-radius: 8px;
    font-size: 0.875rem;
}

.admin-badge-pill {
    display: inline-block;
    padding: 0.2rem 0.55rem;
    border-radius: 999px;
    font-size: 0.72rem;
    font-weight: 600;
}