:root {
    --bg: #FAFAFA; --bg-dark: #0B0F19;
    --bg-card-dark: #1C2230; --bg-cloud: #F7F9FC;
    --fg: #0F172A; --fg-light: #FFFFFF;
    --muted: #F1F5F9; --muted-fg: #64748B; --muted-fg-light: #94A3B8;
    --accent: #0052FF; --accent-2: #2F6BFF; --accent-fg: #FFFFFF;
    --border: #E2E8F0; --border-dark: #2A3344;
    --card: #FFFFFF; --card-dark: #1C2230;
    --huawei-red: #C7000B; --huawei-red-dark: #8A0008; --huawei-red-light: #E60012;
    --tech-blue: #2F6BFF; --data-cyan: #00C2FF; --health-green: #00A86B;
    --gold: #F59E0B; --gold-light: #FCD34D;
    --success: #10B981; --success-light: #D1FAE5;
    --warning: #F59E0B; --warning-light: #FEF3C7;
    --danger: #EF4444; --danger-light: #FEE2E2;
    --font-display: "HarmonyOS Sans SC", "HarmonyOS Sans", "Microsoft YaHei", "微软雅黑", sans-serif;
    --font-body: "HarmonyOS Sans SC", "HarmonyOS Sans", "Microsoft YaHei", "微软雅黑", sans-serif;
    --font-mono: "HarmonyOS Sans SC", Consolas, "Courier New", monospace;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.12);
    --shadow-xl: 0 20px 25px rgba(0,0,0,0.15);
    --shadow-accent: 0 4px 14px rgba(0,82,255,0.3);
    --radius: 12px; --radius-lg: 16px; --radius-xl: 24px;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body { font-family: var(--font-body); background: var(--bg); color: var(--fg); line-height: 1.7; -webkit-font-smoothing: antialiased; }
.container { max-width: 900px; margin: 0 auto; padding: 0 24px; }

/* Unified Top Nav */
.nav { position: fixed; top: 0; left: 0; right: 0; z-index: 1000; background: rgba(250,250,250,0.85); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border-bottom: 1px solid var(--border); transition: background 0.3s, box-shadow 0.3s; }
.nav.scrolled { background: rgba(255,255,255,0.95); box-shadow: var(--shadow-sm); }
.nav-container { max-width: 1200px; margin: 0 auto; padding: 0 24px; height: 60px; display: flex; align-items: center; justify-content: space-between; }
.nav-logo { display: flex; align-items: center; gap: 8px; text-decoration: none; font-family: var(--font-display); font-weight: 800; font-size: 18px; color: var(--fg); }
.nav-logo .logo-icon { font-size: 20px; }
.nav-logo .logo-accent { color: var(--huawei-red); }
.nav-links { display: flex; gap: 24px; align-items: center; }
.nav-links a { font-size: 14px; font-weight: 500; color: var(--muted-fg); text-decoration: none; transition: color 0.2s; }
.nav-links a:hover, .nav-links a.active { color: var(--accent); }
.nav-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--fg); margin: 4px 0; transition: 0.3s; }

/* Guide Sub-Nav (below main nav) */
.guide-nav { position: fixed; top: 60px; left: 0; right: 0; z-index: 999; background: rgba(248,250,252,0.9); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); border-bottom: 1px solid var(--border); }
.guide-nav-container { max-width: 900px; margin: 0 auto; padding: 0 24px; height: 44px; display: flex; align-items: center; justify-content: space-between; }
.guide-nav-back { display: flex; align-items: center; gap: 8px; text-decoration: none; font-family: var(--font-display); font-weight: 700; font-size: 14px; color: var(--fg); }
.guide-nav-back:hover { color: var(--accent); }
.guide-nav-actions { display: flex; gap: 12px; align-items: center; }
.guide-nav-actions a { font-size: 13px; font-weight: 500; color: var(--muted-fg); text-decoration: none; transition: color 0.2s; }
.guide-nav-actions a:hover { color: var(--accent); }

/* Guide Header */
.guide-header { padding: 120px 0 40px; background: linear-gradient(135deg, rgba(0,82,255,0.06) 0%, rgba(77,124,255,0.03) 50%, transparent 100%); border-bottom: 1px solid var(--border); }
.guide-breadcrumb { font-size: 13px; color: var(--muted-fg); margin-bottom: 16px; }
.guide-breadcrumb a { color: var(--accent); text-decoration: none; }
.guide-breadcrumb span { margin: 0 8px; }
.guide-number { display: inline-block; font-family: var(--font-mono); font-size: 13px; font-weight: 600; color: var(--accent); background: rgba(0,82,255,0.08); padding: 4px 12px; border-radius: 100px; margin-bottom: 16px; }
.guide-title { font-family: var(--font-display); font-size: clamp(24px, 4vw, 34px); font-weight: 800; letter-spacing: -0.02em; line-height: 1.2; margin-bottom: 12px; }
.guide-subtitle { font-size: 16px; color: var(--muted-fg); margin-bottom: 24px; }
.guide-meta { display: flex; flex-wrap: wrap; gap: 16px; font-size: 13px; color: var(--muted-fg); }
.guide-meta-item { display: flex; align-items: center; gap: 6px; }
.guide-meta-item strong { color: var(--fg); }

/* Section */
.guide-section { padding: 40px 0; border-bottom: 1px solid var(--border); }
.guide-section:last-of-type { border-bottom: none; }
.guide-section-title { font-family: var(--font-display); font-size: 22px; font-weight: 700; margin-bottom: 8px; display: flex; align-items: center; gap: 10px; }
.guide-section-title .icon { font-size: 24px; }
.guide-section-num { font-family: var(--font-mono); font-size: 14px; font-weight: 600; color: var(--accent); margin-right: 4px; }
.guide-section-desc { font-size: 14px; color: var(--muted-fg); margin-bottom: 20px; }

/* Content elements */
.guide-content p { margin-bottom: 12px; font-size: 15px; }
.guide-content ul, .guide-content ol { margin: 12px 0 12px 24px; }
.guide-content li { margin-bottom: 6px; font-size: 15px; }
.guide-content strong { color: var(--fg); }
.guide-content code { font-family: var(--font-mono); font-size: 13px; color: var(--accent); background: rgba(0,82,255,0.06); padding: 2px 6px; border-radius: 4px; }

/* Info boxes */
.info-box { border-radius: var(--radius); padding: 16px 20px; margin: 16px 0; font-size: 14px; line-height: 1.6; }
.info-box-title { font-weight: 700; margin-bottom: 4px; display: flex; align-items: center; gap: 8px; }
.info-box-tip { background: var(--success-light); border-left: 4px solid var(--success); color: #065F46; }
.info-box-warn { background: var(--warning-light); border-left: 4px solid var(--warning); color: #92400E; }
.info-box-note { background: rgba(0,82,255,0.06); border-left: 4px solid var(--accent); color: #1E40AF; }

/* Topology diagram */
.topo-diagram { background: var(--bg-dark); border-radius: var(--radius-lg); padding: 24px; margin: 16px 0; overflow-x: auto; }
.topo-diagram pre { font-family: var(--font-mono); font-size: 13px; color: #E0E7FF; line-height: 1.5; white-space: pre; }
.topo-diagram .label { color: var(--accent-2); }
.topo-diagram .device { color: var(--gold-light); font-weight: 700; }
.topo-diagram .link { color: var(--muted-fg-light); }

/* Device table */
.device-table { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: 13px; }
.device-table th { background: var(--bg-dark); color: var(--fg-light); padding: 10px 14px; text-align: left; font-weight: 600; font-size: 12px; }
.device-table th:first-child { border-radius: 8px 0 0 0; }
.device-table th:last-child { border-radius: 0 8px 0 0; }
.device-table td { padding: 10px 14px; border-bottom: 1px solid var(--border); }
.device-table tr:nth-child(even) { background: var(--muted); }
.device-table code { font-family: var(--font-mono); font-size: 12px; }

/* Config steps */
.config-step { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 20px 24px; margin: 16px 0; }
.config-step-header { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; }
.config-step-num { width: 32px; height: 32px; border-radius: 50%; background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: white; font-family: var(--font-display); font-size: 15px; font-weight: 800; display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.config-step-title { font-family: var(--font-display); font-size: 16px; font-weight: 700; }
.config-step-desc { font-size: 14px; color: var(--muted-fg); margin-bottom: 12px; }

/* CLI block */
.cli-block { background: #1a1a2e; border-radius: var(--radius); overflow: hidden; margin: 12px 0; }
.cli-block-header { display: flex; align-items: center; gap: 8px; padding: 10px 14px; background: #16162a; border-bottom: 1px solid #2a2a4a; }
.cli-dot { width: 10px; height: 10px; border-radius: 50%; }
.cli-dot-red { background: #ff5f56; }
.cli-dot-yellow { background: #ffbd2e; }
.cli-dot-green { background: #27c93f; }
.cli-block-title { font-size: 12px; color: var(--muted-fg-light); margin-left: 8px; font-family: var(--font-mono); }
.cli-block-body { padding: 16px; font-family: var(--font-mono); font-size: 13px; color: #e0e0e0; line-height: 1.6; overflow-x: auto; white-space: pre; }
.cli-block-body .cmd { color: #E0E7FF; }
.cli-block-body .prompt { color: var(--accent-2); }
.cli-block-body .comment { color: #6B7280; font-style: italic; }
.cli-block-body .output { color: #9CA3AF; }

/* Verify table */
.verify-table { width: 100%; border-collapse: collapse; margin: 16px 0; font-size: 14px; }
.verify-table th { background: var(--muted); padding: 10px 14px; text-align: left; font-weight: 600; font-size: 13px; color: var(--fg); }
.verify-table td { padding: 10px 14px; border-bottom: 1px solid var(--border); }
.verify-table .pass { color: var(--success); font-weight: 600; }
.verify-table .fail { color: var(--danger); font-weight: 600; }
.verify-table code { font-family: var(--font-mono); font-size: 12px; color: var(--accent); background: rgba(0,82,255,0.06); padding: 2px 6px; border-radius: 4px; }

/* Questions */
.question-list { counter-reset: q; list-style: none; margin: 0; padding: 0; }
.question-list li { counter-increment: q; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px 20px 16px 56px; margin-bottom: 12px; position: relative; font-size: 15px; }
.question-list li::before { content: "Q" counter(q); position: absolute; left: 16px; top: 16px; font-family: var(--font-mono); font-size: 13px; font-weight: 700; color: var(--accent); background: rgba(0,82,255,0.08); padding: 4px 10px; border-radius: 100px; }
.question-list li .hint { display: block; margin-top: 8px; font-size: 13px; color: var(--muted-fg); font-style: italic; }

/* Guide footer — unified format */
.footer { background: var(--bg-dark); color: var(--muted-fg-light); padding: 48px 0 24px; margin-top: 40px; }
.footer .container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.footer-top { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 32px; }
.footer-brand { display: flex; flex-direction: column; gap: 8px; }
.footer-logo { font-family: var(--font-display); font-size: 18px; font-weight: 800; color: var(--fg-light); }
.footer-brand p { font-size: 13px; color: var(--muted-fg-light); }
.footer-col h5 { font-size: 14px; font-weight: 700; color: var(--fg-light); margin-bottom: 12px; }
.footer-col a { display: block; font-size: 13px; color: var(--muted-fg-light); text-decoration: none; margin-bottom: 8px; transition: color 0.2s; }
.footer-col a:hover { color: var(--accent-2); }
.footer-bottom { display: flex; justify-content: space-between; align-items: center; padding-top: 24px; border-top: 1px solid var(--border-dark); font-size: 13px; }
.footer-bottom p { color: var(--muted-fg-light); }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; font-family: var(--font-body); font-weight: 600; font-size: 14px; border-radius: var(--radius); padding: 10px 22px; text-decoration: none; border: none; cursor: pointer; transition: all 0.2s ease-out; white-space: nowrap; }
.btn-sm { padding: 7px 16px; font-size: 13px; }
.btn-primary { background: var(--accent); color: var(--accent-fg); box-shadow: var(--shadow-accent); }
.btn-primary:hover { background: var(--accent-2); transform: translateY(-1px); }
.btn-ghost { background: transparent; color: var(--fg); border: 1px solid var(--border); }
.btn-ghost:hover { background: var(--muted); border-color: var(--muted-fg); }

/* Nav prev/next */
.guide-nav-bottom { display: flex; justify-content: space-between; gap: 16px; padding: 32px 0; flex-wrap: wrap; }
.guide-nav-bottom a { flex: 1; min-width: 200px; text-decoration: none; }
.nav-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 16px 20px; transition: all 0.2s; }
.nav-card:hover { border-color: var(--accent-2); box-shadow: var(--shadow-md); }
.nav-card-label { font-size: 12px; color: var(--muted-fg); margin-bottom: 4px; }
.nav-card-title { font-family: var(--font-display); font-size: 15px; font-weight: 700; }
.nav-card.next { text-align: right; }

/* Responsive */
@media (max-width: 768px) {
    .nav-links { display: none; position: absolute; top: 60px; left: 0; right: 0; background: var(--card); flex-direction: column; padding: 16px 24px; gap: 12px; box-shadow: var(--shadow-md); }
    .nav-links.open { display: flex; }
    .nav-toggle { display: block; }
    .guide-nav-actions { display: none; }
    .device-table, .verify-table { font-size: 12px; }
    .device-table th, .device-table td, .verify-table th, .verify-table td { padding: 8px 10px; }
    .cli-block-body { font-size: 12px; }
    .guide-nav-bottom { flex-direction: column; }
    .nav-card.next { text-align: left; }
    .footer-top { grid-template-columns: 1fr; gap: 24px; }
}