/* === Design Tokens === */
:root {
    --color-bg: #f8f9fa;
    --color-surface: #ffffff;
    --color-text: #1a1a2e;
    --color-text-secondary: #6b7280;
    --color-border: #e5e7eb;
    --color-primary: #2563eb;
    --color-primary-hover: #1d4ed8;
    --color-success: #16a34a;
    --color-success-bg: #dcfce7;
    --color-danger: #dc2626;
    --color-danger-hover: #b91c1c;
    --color-danger-bg: #fee2e2;
    --color-amber: #d97706;
    --color-amber-bg: #fef3c7;
    --color-input-bg: #ffffff;
    --color-input-border: #d1d5db;
    --color-nav-bg: #1e293b;
    --color-nav-text: #f1f5f9;
    --color-card-hover: #f1f5f9;
    --radius: 8px;
    --radius-sm: 4px;
    --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
    --font-mono: 'SF Mono', 'Cascadia Code', 'Fira Code', 'Consolas', monospace;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
}

@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #0f172a;
        --color-surface: #1e293b;
        --color-text: #e2e8f0;
        --color-text-secondary: #94a3b8;
        --color-border: #334155;
        --color-primary: #3b82f6;
        --color-primary-hover: #60a5fa;
        --color-success-bg: #052e16;
        --color-danger-bg: #450a0a;
        --color-amber-bg: #451a03;
        --color-input-bg: #0f172a;
        --color-input-border: #475569;
        --color-nav-bg: #020617;
        --color-card-hover: #334155;
        --shadow: 0 1px 3px rgba(0,0,0,0.3);
        --shadow-md: 0 4px 6px rgba(0,0,0,0.3);
    }
}

/* === Accessibility === */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.skip-link {
    position: absolute;
    top: -100%;
    left: var(--space-md);
    z-index: 1000;
    padding: var(--space-sm) var(--space-md);
    background: var(--color-primary);
    color: #fff;
    border-radius: 0 0 var(--radius-sm) var(--radius-sm);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.875rem;
}
.skip-link:focus {
    top: 0;
}

/* === Reset === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
    font-family: var(--font-sans);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
}

/* High-visibility focus indicators */
:focus-visible {
    outline: 3px solid var(--color-primary);
    outline-offset: 2px;
}

.btn:focus-visible {
    outline: 3px solid var(--color-primary);
    outline-offset: 2px;
    box-shadow: 0 0 0 5px rgba(37,99,235,0.2);
}

.form-group input:focus-visible,
.ip-form textarea:focus-visible {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(37,99,235,0.25);
}

/* === Layout === */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-md);
}

/* === Navbar === */
.navbar {
    background: var(--color-nav-bg);
    color: var(--color-nav-text);
    padding: var(--space-sm) 0;
    margin-bottom: var(--space-xl);
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-brand {
    color: var(--color-nav-text);
    text-decoration: none;
    font-weight: 700;
    font-size: 1.1rem;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.nav-link {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    transition: color 0.15s, background 0.15s;
}
.nav-link:hover {
    color: var(--color-nav-text);
    background: rgba(255,255,255,0.1);
}

.nav-user {
    color: var(--color-text-secondary);
    font-size: 0.875rem;
}

/* === Alerts === */
.alert {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-sm);
    margin-bottom: var(--space-md);
    font-size: 0.9rem;
}
.alert-success { background: var(--color-success-bg); color: var(--color-success); border: 1px solid var(--color-success); }
.alert-danger { background: var(--color-danger-bg); color: var(--color-danger); border: 1px solid var(--color-danger); }

.alert-dismiss {
    background: none;
    border: none;
    color: inherit;
    font-size: 1.2rem;
    cursor: pointer;
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
    line-height: 1;
    flex-shrink: 0;
    opacity: 0.7;
}
.alert-dismiss:hover,
.alert-dismiss:focus-visible {
    opacity: 1;
}

/* === Page Header === */
.page-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
    flex-wrap: wrap;
}

.page-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
}

.page-actions {
    display: flex;
    gap: var(--space-sm);
    align-items: center;
}

/* === Status Bar === */
.status-bar {
    display: flex;
    gap: var(--space-lg);
    flex-wrap: wrap;
    padding: var(--space-sm) var(--space-md);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    margin-bottom: var(--space-lg);
    font-size: 0.85rem;
    color: var(--color-text-secondary);
}
.status-bar code {
    font-family: var(--font-mono);
    font-size: 0.85rem;
}

/* === Network Grid === */
.network-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: var(--space-md);
}

.network-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: var(--space-md);
    text-decoration: none;
    color: var(--color-text);
    transition: box-shadow 0.15s, border-color 0.15s;
    display: block;
}
.network-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary);
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-sm);
}

.card-title {
    font-size: 1rem;
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.card-body {
    font-size: 0.875rem;
}

.card-detail {
    margin-top: var(--space-xs);
    color: var(--color-text-secondary);
}
.card-detail .label {
    font-weight: 500;
    color: var(--color-text);
}

.network-id {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--color-text-secondary);
}

/* === Detail Grid === */
.detail-grid {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-lg);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: var(--space-md);
    margin-bottom: var(--space-xl);
}

dl.detail-grid {
    margin: 0;
}
dl.detail-grid dt,
dl.detail-grid dd {
    margin: 0;
    padding: 0;
}

.detail-item {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}
.detail-item .label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-secondary);
    font-weight: 600;
}
.detail-item code {
    font-family: var(--font-mono);
    font-size: 0.85rem;
}

/* === Status Toggle === */
.status-toggle {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

/* === Badges === */
.badge {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    white-space: nowrap;
}
.badge-green { background: var(--color-success-bg); color: var(--color-success); }
.badge-amber { background: var(--color-amber-bg); color: var(--color-amber); }

/* === Table === */
.table-wrap {
    overflow-x: auto;
    margin-bottom: var(--space-lg);
}

.table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
}
.table th, .table td {
    padding: var(--space-sm) var(--space-md);
    text-align: left;
    border-bottom: 1px solid var(--color-border);
}
.table th {
    font-weight: 600;
    color: var(--color-text-secondary);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: var(--color-surface);
}
.table td code {
    font-family: var(--font-mono);
    font-size: 0.8rem;
}

.ip-addr {
    font-family: var(--font-mono);
    display: inline-block;
    background: var(--color-bg);
    padding: 1px 6px;
    border-radius: var(--radius-sm);
    margin: 1px 2px;
    font-size: 0.8rem;
}

.action-cell {
    display: flex;
    gap: var(--space-xs);
    flex-wrap: wrap;
}

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

/* === IP Form Row === */
.ip-form-row td {
    background: var(--color-bg);
    border-bottom: 2px solid var(--color-border);
}

.ip-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    max-width: 400px;
}
.ip-form textarea {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    padding: var(--space-sm);
    border: 1px solid var(--color-input-border);
    border-radius: var(--radius-sm);
    background: var(--color-input-bg);
    color: var(--color-text);
    resize: vertical;
}

/* === Routes Section === */
.routes-section {
    margin-bottom: var(--space-xl);
}

.routes-section h2 {
    margin-bottom: var(--space-md);
}

.route-add-form {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: var(--space-md);
}

.route-add-form fieldset {
    border: none;
    padding: 0;
    margin: 0;
}

.route-add-form legend {
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: var(--space-md);
}

.route-add-fields {
    display: flex;
    gap: var(--space-md);
    align-items: flex-end;
    flex-wrap: wrap;
}

.route-add-fields .form-group {
    flex: 1;
    min-width: 180px;
    margin-bottom: 0;
}

.route-add-action {
    flex: 0 0 auto;
}

/* === Buttons === */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
    border: 1px solid transparent;
    cursor: pointer;
    transition: background 0.15s, border-color 0.15s;
    font-family: inherit;
    line-height: 1.4;
}
.btn-sm {
    padding: 3px 10px;
    font-size: 0.8rem;
}
.btn-primary {
    background: var(--color-primary);
    color: #fff;
    border-color: var(--color-primary);
}
.btn-primary:hover { background: var(--color-primary-hover); }
.btn-outline {
    background: transparent;
    color: var(--color-text);
    border-color: var(--color-border);
}
.btn-outline:hover { background: var(--color-card-hover); }
.btn-danger {
    background: var(--color-danger);
    color: #fff;
    border-color: var(--color-danger);
}
.btn-danger:hover { background: var(--color-danger-hover); }
.btn-block { width: 100%; }

/* === Forms === */
.form-panel {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: var(--space-lg);
    max-width: 560px;
}

.form-group {
    margin-bottom: var(--space-md);
}
.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: var(--space-xs);
    font-size: 0.875rem;
}
.form-group input[type="text"],
.form-group input[type="password"] {
    width: 100%;
    padding: var(--space-sm) var(--space-md);
    border: 1px solid var(--color-input-border);
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    background: var(--color-input-bg);
    color: var(--color-text);
    font-family: inherit;
}
.form-group input:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(37,99,235,0.25);
}
.form-help {
    display: block;
    margin-top: var(--space-xs);
    font-size: 0.8rem;
    color: var(--color-text-secondary);
}

.form-actions {
    display: flex;
    gap: var(--space-sm);
    margin-top: var(--space-lg);
}

.inline-form {
    display: inline;
}

/* === Login Page === */
.login-page {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: var(--space-md);
}

.login-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: var(--space-xl);
    box-shadow: var(--shadow-md);
    width: 100%;
    max-width: 400px;
}
.login-card h1 {
    font-size: 1.3rem;
    margin-bottom: var(--space-lg);
    text-align: center;
}

/* === Misc === */
.empty-state {
    text-align: center;
    color: var(--color-text-secondary);
    padding: var(--space-xl);
    font-size: 0.95rem;
}

.back-link {
    margin-top: var(--space-lg);
}
.back-link a {
    color: var(--color-primary);
    text-decoration: none;
    font-size: 0.9rem;
}
.back-link a:hover { text-decoration: underline; }

.footer {
    margin-top: var(--space-xl);
    padding: var(--space-md) 0;
    text-align: center;
    color: var(--color-text-secondary);
    border-top: 1px solid var(--color-border);
}

/* === Responsive === */
@media (max-width: 768px) {
    .network-grid {
        grid-template-columns: 1fr;
    }
    .page-header {
        flex-direction: column;
    }
    .status-bar {
        flex-direction: column;
        gap: var(--space-sm);
    }
    .detail-grid {
        flex-direction: column;
    }
    .action-cell {
        flex-direction: column;
    }
    .route-add-fields {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--space-sm);
    }
    .form-panel {
        padding: var(--space-md);
    }
    .login-card {
        padding: var(--space-md);
    }
}