*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  line-height: 1.7;
  font-size: 16px;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
}

body.guide-page {
  --page-accent: var(--accent);
  --page-accent-soft: var(--accent-glow);
  --page-accent-strong: var(--text-bright);
  --page-surface: var(--bg-card);
  --page-surface-strong: var(--bg-card);
  --page-chip: rgba(184, 131, 46, 0.08);
  --page-shadow: none;
}

.dark body.guide-page {
  --page-accent: var(--accent);
  --page-accent-soft: var(--accent-glow);
  --page-accent-strong: var(--text-bright);
  --page-surface: var(--bg-card);
  --page-surface-strong: var(--bg-card);
  --page-chip: rgba(212, 168, 75, 0.1);
  --page-shadow: none;
}

a {
  color: var(--page-accent);
  text-decoration: none;
}

a:hover {
  color: var(--text-bright);
}

::selection {
  background: var(--page-accent);
  color: #fff;
}

nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 20px 0;
  background: var(--nav-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  transition: background .4s, backdrop-filter .4s;
}

nav .container,
.container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 48px;
}

nav .container {
  display: flex;
  align-items: center;
}

nav .logo {
  font-family: var(--sans-en);
  font-size: 1.15rem;
  color: var(--text-bright);
  font-weight: 700;
  letter-spacing: -.01em;
  line-height: 1.2;
  text-decoration: none;
}

nav .logo span { color: var(--page-accent); }
nav ul { list-style: none; display: flex; gap: 36px; margin: 0 0 0 auto; padding: 0; }
nav ul a {
  font-family: var(--sans-en);
  font-size: .68rem;
  color: var(--text-dim);
  letter-spacing: .1em;
  text-transform: uppercase;
  font-weight: 500;
  transition: color .3s;
  line-height: 1.2;
}

nav ul a:hover,
nav ul a.active { color: var(--page-accent); }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
  z-index: 101;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  min-width: 44px;
  min-height: 44px;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text-bright);
  border-radius: 1px;
  transition: transform .3s, opacity .3s;
}

.nav-toggle.open span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

.page-header {
  padding: 138px 0 18px;
}

.shanghai-head {
  max-width: 760px;
  padding: 0;
}

.head-copy[data-lang="en"] {
  display: none;
}

html.lang-en .head-copy[data-lang="zh"] {
  display: none;
}

html.lang-en .head-copy[data-lang="en"] {
  display: block;
}

.sec-hd .tag {
  display: block;
  margin-bottom: 12px;
  color: var(--page-accent);
  font-family: var(--sans-en);
  font-size: .7rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  font-weight: 700;
}

.sec-hd h1,
.sec-hd .localized-title {
  margin: 0;
  color: var(--text-bright);
  font-size: clamp(2.1rem, 4.5vw, 3.7rem);
  font-weight: 800;
  letter-spacing: -.05em;
  line-height: 1;
}

.sec-hd .sub {
  margin: 14px 0 0;
  max-width: 640px;
  color: var(--text-dim);
  font-size: .98rem;
  line-height: 1.72;
}

.intro-keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.intro-keywords span {
  display: inline-flex;
  align-items: center;
  padding: 7px 11px;
  border-radius: 999px;
  background: var(--page-chip);
  color: var(--page-accent);
  font-family: var(--sans-en);
  font-size: .69rem;
  font-weight: 700;
  letter-spacing: .02em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.section-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

.section-pill {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: 0 18px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--page-surface);
  color: var(--text);
  font-weight: 700;
  transition: border-color .22s ease, color .22s ease, background .22s ease;
}

.section-pill:hover {
  color: var(--text-bright);
  border-color: var(--border-light);
  background: rgba(24, 20, 14, 0.03);
}

.hero-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 16px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--bg);
  color: var(--text);
  font-weight: 700;
  transition: transform .22s ease, border-color .22s ease, color .22s ease;
}

.hero-action:hover {
  transform: translateY(-1px);
  border-color: var(--page-accent);
}

.hero-action.primary {
  background: var(--page-chip);
  color: var(--page-accent);
  border-color: rgba(184, 131, 46, 0.22);
}

.hero-stat-card,
.journey-card,
.guide-feature-intro {
  border: 1px solid var(--border);
  border-radius: 28px;
  background: var(--page-surface);
  box-shadow: var(--page-shadow);
}

.hero-rail-kicker,
.journey-step {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 52px;
  padding: 7px 12px;
  border-radius: 999px;
  background: var(--page-chip);
  color: var(--page-accent);
  font-family: var(--sans-en);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
}

.journey-head h2,
.guide-feature-intro h2 {
  margin: 14px 0 0;
  color: var(--text-bright);
  letter-spacing: -.04em;
  line-height: 1.12;
}

.hero-rail-list {
  margin: 16px 0 0;
  padding-left: 20px;
  color: var(--text-dim);
  line-height: 1.8;
}

.hero-rail-list li + li {
  margin-top: 8px;
}

.hero-stat-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.hero-stat-card {
  padding: 18px;
}

.hero-stat-label {
  display: block;
  color: var(--text-dim);
  font-family: var(--sans-en);
  font-size: .72rem;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.hero-stat-card strong {
  display: block;
  margin-top: 10px;
  color: var(--text-bright);
  font-size: 2rem;
  line-height: 1;
}

.seo-intro-section,
.seo-faq-section,
.guide-links-section,
.article-section,
.journey-section {
  padding: 0 0 36px;
}

.guide-links-grid,
.related-links-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.guide-link-card,
.article-card,
.article-summary,
.article-section-card {
  border: 1px solid var(--border);
  border-radius: 28px;
  background: var(--page-surface);
  box-shadow: var(--page-shadow);
}

.guide-link-card,
.article-summary,
.article-section-card {
  padding: 22px 24px;
}

.guide-link-card {
  display: block;
  transition: transform .25s ease, border-color .25s ease, background .25s ease;
}

.guide-link-card:hover {
  transform: translateY(-2px);
  border-color: var(--page-accent);
}

.guide-link-card h3,
.article-card h2,
.article-section-card h2,
.article-section-card h3 {
  margin: 0;
  color: var(--text-bright);
}

.guide-link-card h3 {
  font-size: 1.08rem;
  line-height: 1.42;
}

.guide-link-card p,
.guide-link-card ul,
.article-summary p,
.article-section-card p,
.article-section-card li,
.article-kicker,
.article-note,
.related-links-grid p {
  color: var(--text-dim);
}

.guide-link-card p,
.article-summary p,
.article-section-card p {
  margin: 12px 0 0;
  line-height: 1.8;
}

.guide-link-card ul,
.article-section-card ul {
  margin: 14px 0 0;
  padding-left: 20px;
}

.guide-link-card li + li,
.article-section-card li + li {
  margin-top: 6px;
}

.guide-link-meta,
.article-kicker {
  display: inline-flex;
  align-items: center;
  margin-bottom: 12px;
  color: var(--page-accent);
  font-family: var(--sans-en);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
}

.article-layout {
  max-width: 860px;
}

.article-summary {
  margin-bottom: 18px;
}

.article-summary h2 {
  margin: 0;
  color: var(--text-bright);
  font-size: clamp(1.55rem, 3vw, 2.1rem);
  letter-spacing: -.03em;
  line-height: 1.15;
}

.article-summary .answer-lead {
  margin-top: 16px;
  color: var(--text);
  font-size: 1.06rem;
}

.article-note {
  margin-top: 14px;
  font-size: .95rem;
}

.article-card {
  overflow: hidden;
}

.article-card + .article-card {
  margin-top: 16px;
}

.article-card h2 {
  padding: 22px 24px 0;
  font-size: 1.3rem;
  letter-spacing: -.02em;
  line-height: 1.25;
}

.article-section-card {
  border: 0;
  border-top: 1px solid var(--border);
  border-radius: 0;
  background: transparent;
  box-shadow: none;
}

.article-section-card:first-of-type {
  border-top: 0;
}

.article-highlight-list {
  margin: 16px 0 0;
  padding-left: 20px;
}

.article-highlight-list li + li {
  margin-top: 8px;
}

.related-links-grid {
  margin-top: 18px;
}

.seo-intro-card,
.seo-faq-item {
  border: 1px solid var(--border);
  border-radius: 28px;
  background: var(--page-surface);
  box-shadow: var(--page-shadow);
}

.seo-intro-card {
  padding: 28px;
}

.seo-kicker {
  margin: 0 0 10px;
  color: var(--page-accent);
  text-transform: uppercase;
  font-family: var(--sans-en);
  font-size: .68rem;
  letter-spacing: .14em;
  font-weight: 700;
}

.seo-intro-card h2,
.seo-section-head h2,
.seo-faq-item h3 {
  margin: 0;
  color: var(--text-bright);
}

.seo-intro-card h2,
.seo-section-head h2 {
  font-size: clamp(1.7rem, 3vw, 2.4rem);
  letter-spacing: -.04em;
  line-height: 1.12;
}

.seo-intro-card p,
.seo-section-head p,
.seo-faq-answer,
.seo-faq-zh {
  color: var(--text-dim);
}

.seo-intro-card p {
  margin: 14px 0 0;
  line-height: 1.85;
}

.seo-section-head {
  max-width: 760px;
  margin-bottom: 18px;
}

.journey-head {
  max-width: 760px;
  margin-bottom: 26px;
}

.journey-head p {
  margin: 10px 0 0;
  color: var(--text-dim);
  line-height: 1.8;
}

.question-browser + .question-browser {
  margin-top: 8px;
}

.question-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 30px;
  margin: 0 0 20px;
}

.question-filter {
  border: 0;
  background: transparent;
  cursor: pointer;
  padding: 0;
  color: var(--text-dim);
  font-family: var(--sans);
  font-size: .82rem;
  font-weight: 400;
  transition: color .22s ease;
}

.question-filter:hover,
.question-filter.active {
  color: var(--text-bright);
}

.question-filter.active {
  font-weight: 600;
}

.question-count {
  margin-left: 4px;
  font-size: .7rem;
  opacity: .45;
}

.question-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--border);
  border-top: 1px solid var(--border);
}

[hidden] { display: none !important; }

.question-link {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-height: 188px;
  padding: 36px 32px 32px;
  background: var(--bg);
  color: inherit;
  text-decoration: none;
  transition: background .28s ease;
}

.question-link:hover {
  background: rgba(24, 20, 14, 0.03);
}

.question-link-meta {
  display: inline-flex;
  align-items: center;
  color: var(--text-dim);
  font-family: var(--sans-en);
  font-size: .62rem;
  letter-spacing: .1em;
  opacity: .4;
  text-transform: uppercase;
}

.question-link h3 {
  margin: 0;
  color: var(--text-bright);
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.35;
}

.journey-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin-top: 18px;
}

.journey-card {
  padding: 22px;
}

.journey-card h3 {
  margin: 14px 0 0;
  color: var(--text-bright);
  font-size: 1.18rem;
  line-height: 1.25;
}

.journey-card p {
  margin: 12px 0 0;
  color: var(--text-dim);
  line-height: 1.8;
}

.journey-link {
  display: inline-flex;
  margin-top: 18px;
  color: var(--page-accent);
  font-weight: 700;
}

.seo-section-head p {
  margin: 10px 0 0;
  line-height: 1.8;
}

.seo-faq-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.seo-faq-item {
  padding: 22px 22px 20px;
}

.seo-faq-item h3 {
  font-size: 1.1rem;
  line-height: 1.5;
}

.seo-faq-answer,
.seo-faq-zh {
  margin: 12px 0 0;
  line-height: 1.75;
}

.seo-faq-answer {
  color: var(--text);
}

.guide-section {
  padding: 0 0 72px;
}

.workbench-head {
  margin-bottom: 20px;
}

.app-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 22px;
  align-items: start;
}

.sidebar,
.hero,
.faq-card,
.summary-panel,
.metric-card,
.empty-state {
  border: 1px solid var(--border);
  box-shadow: var(--page-shadow);
}

.sidebar {
  position: sticky;
  top: 104px;
  padding: 28px 20px;
  border-radius: 28px;
  background: var(--page-surface-strong);
}

.brand h2,
.hero h2 {
  margin: 0;
  color: var(--text-bright);
  line-height: 1.08;
}

.brand h2 {
  font-size: 2rem;
  letter-spacing: -.05em;
}

.subtitle,
.hero-copy,
.search-label,
.sidebar-title,
.summary-list,
.results-header,
.faq-meta,
.faq-answer,
.faq-tags {
  color: var(--text-dim);
}

.subtitle {
  margin-top: 10px;
  line-height: 1.75;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--page-accent);
  text-transform: uppercase;
  font-family: var(--sans-en);
  font-size: 12px;
  letter-spacing: .14em;
  font-weight: 700;
}

.sidebar-block { margin-top: 28px; }

.search-label,
.sidebar-title {
  display: block;
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 10px;
}

.search-input,
.lang-switch,
.category-button,
.ghost-button,
.metric-card {
  border: 1px solid var(--border);
  background: var(--bg);
}

.dark .search-input,
.dark .lang-switch,
.dark .category-button,
.dark .ghost-button,
.dark .metric-card {
  background: var(--bg);
}

.search-input {
  width: 100%;
  padding: 14px 16px;
  border-radius: 14px;
  font-size: 15px;
  color: var(--text);
}

.search-input:focus {
  outline: 2px solid var(--page-accent-soft);
  border-color: var(--page-accent);
}

.category-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.lang-switch {
  display: inline-flex;
  gap: 8px;
  padding: 6px;
  border-radius: 14px;
}

.lang-button,
.ghost-button {
  color: var(--text);
  font-family: inherit;
}

.lang-button {
  border: 0;
  background: transparent;
  padding: 9px 14px;
  border-radius: 10px;
  cursor: pointer;
  font-weight: 700;
}

.lang-button.active {
  background: var(--page-chip);
  color: var(--page-accent);
}

.category-button {
  border-radius: 14px;
  padding: 12px 14px;
  text-align: left;
  cursor: pointer;
  transition: .18s ease;
}

.category-button:hover {
  border-color: var(--page-accent);
  transform: translateY(-1px);
}

.category-button.active {
  background: var(--page-chip);
  border-color: var(--page-accent);
}

.category-name {
  display: block;
  color: var(--text);
  font-weight: 700;
}

.category-count {
  display: block;
  margin-top: 4px;
  font-size: 13px;
  color: var(--text-dim);
}

.summary-panel {
  border-radius: 22px;
  padding: 16px;
  background: var(--page-surface);
}

.summary-list {
  margin: 0;
  padding-left: 18px;
  line-height: 1.8;
}

.main-panel {
  min-width: 0;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) 280px;
  gap: 20px;
  padding: 28px;
  border-radius: 28px;
  background: var(--page-surface-strong);
}

.dark .hero {
  background: var(--page-surface-strong);
}

.hero h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  letter-spacing: -.06em;
}

.hero-copy {
  margin-top: 14px;
  max-width: 760px;
  line-height: 1.85;
}

.hero-meta {
  display: grid;
  gap: 14px;
}

.metric-card {
  border-radius: 20px;
  padding: 18px;
}

.metric-label {
  display: block;
  color: var(--text-dim);
  font-size: 13px;
}

.metric-card strong {
  display: block;
  margin-top: 8px;
  color: var(--text-bright);
  font-size: 2rem;
}

.toolbar {
  margin-top: 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.active-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.filter-chip,
.tag-chip {
  display: inline-flex;
  align-items: center;
  padding: 8px 12px;
  border-radius: 999px;
  background: var(--page-chip);
  color: var(--page-accent);
  font-size: 13px;
  font-weight: 700;
}

.tag-chip {
  color: var(--page-accent-strong);
}

.ghost-button {
  padding: 10px 14px;
  border-radius: 12px;
  cursor: pointer;
}

.results-header {
  margin-top: 18px;
  font-size: 14px;
}

.faq-grid {
  margin-top: 16px;
  display: grid;
  gap: 14px;
}

.faq-card {
  overflow: hidden;
  border-radius: 22px;
  background: var(--page-surface);
}

.faq-question {
  width: 100%;
  border: 0;
  background: transparent;
  color: inherit;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 14px;
  align-items: center;
  padding: 18px 20px;
  cursor: pointer;
  text-align: left;
}

.faq-priority {
  min-width: 46px;
  padding: 6px 10px;
  border-radius: 999px;
  background: var(--page-chip);
  color: var(--page-accent);
  font-size: 12px;
  font-weight: 800;
  text-align: center;
}

.faq-title {
  color: var(--text-bright);
  font-size: 19px;
  font-weight: 800;
  line-height: 1.45;
}

.faq-toggle {
  font-size: 28px;
  color: var(--text-dim);
  line-height: 1;
}

.faq-card.open .faq-toggle { transform: rotate(45deg); }

.faq-body {
  display: none;
  padding: 0 20px 20px;
  border-top: 1px solid var(--border);
}

.faq-card.open .faq-body { display: block; }

.faq-meta {
  margin: 14px 0 0;
  font-size: 14px;
}

.faq-answer {
  margin-top: 14px;
  line-height: 1.85;
  color: var(--text);
}

.faq-answer h4 {
  margin: 18px 0 8px;
  font-size: 15px;
  color: var(--page-accent);
}

.faq-answer ul,
.faq-answer ol {
  margin: 8px 0 0;
  padding-left: 20px;
}

.faq-answer li + li { margin-top: 6px; }

.faq-answer code {
  padding: 2px 6px;
  border-radius: 8px;
  background: var(--page-chip);
  color: var(--page-accent-strong);
  font-family: var(--mono);
  font-size: .85em;
}

.faq-tags {
  margin-top: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.empty-state {
  padding: 28px;
  border-radius: 22px;
  border-style: dashed;
  background: var(--page-surface);
  color: var(--text-dim);
  line-height: 1.7;
}

footer {
  border-top: 1px solid var(--border);
  padding: 28px 0 calc(28px + env(safe-area-inset-bottom, 0px));
  text-align: center;
}

footer p {
  font-family: var(--sans-en);
  font-size: .68rem;
  color: var(--text-dim);
  letter-spacing: .06em;
}

footer p span { color: var(--page-accent); }

.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity .7s cubic-bezier(.22, 1, .36, 1), transform .7s cubic-bezier(.22, 1, .36, 1);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-d1 { transition-delay: .08s; }
.reveal-d2 { transition-delay: .16s; }

@media (max-width: 1040px) {
  .journey-grid,
  .app-shell,
  .hero,
  .seo-faq-grid,
  .guide-links-grid,
  .related-links-grid {
    grid-template-columns: 1fr;
  }

  .question-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .sidebar {
    position: static;
  }
}

@media (max-width: 768px) {
  nav .container,
  .container {
    padding: 0 28px;
  }

  .page-header {
    padding-top: 126px;
  }

  .shanghai-head {
    max-width: 100%;
  }

  .seo-intro-card,
  .seo-faq-item {
    border-radius: 24px;
  }
}

@media (max-width: 640px) {
  nav {
    z-index: 10000;
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
  }

  .nav-toggle {
    display: flex;
    z-index: 10001;
  }

  .theme-toggle { margin-left: auto !important; }

  nav ul {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    margin: 0;
    display: flex;
    background: var(--bg);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 28px;
    opacity: 0;
    pointer-events: none;
    transition: opacity .35s;
  }

  nav ul.open {
    opacity: 1;
    pointer-events: auto;
  }

  nav ul a {
    font-size: 1.1rem;
    letter-spacing: .06em;
  }

  .container {
    padding: 0 18px;
  }

  .main-panel,
  .sidebar,
  .hero,
  .seo-intro-card,
  .seo-faq-item,
  .guide-link-card,
  .article-summary,
  .article-section-card,
  .journey-card,
  .shanghai-head,
  .hero-stat-card {
    padding-left: 18px;
    padding-right: 18px;
  }

  .sidebar,
  .hero,
  .seo-intro-card,
  .seo-faq-item,
  .guide-link-card,
  .article-summary,
  .article-card,
  .journey-card,
  .shanghai-head,
  .hero-stat-card {
    border-radius: 24px;
  }

  .toolbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .faq-question {
    grid-template-columns: 1fr auto;
  }

  .faq-priority {
    grid-column: 1 / -1;
    justify-self: start;
  }

  .intro-keywords {
    gap: 8px;
  }

  .intro-keywords span {
    font-size: .68rem;
  }

  .section-pills {
    gap: 10px;
  }

  .question-filters {
    gap: 10px 18px;
  }

  .question-grid {
    grid-template-columns: 1fr;
  }

  .question-link {
    min-height: 0;
    padding: 26px 18px 24px;
  }

  .hero-actions,
  .hero-stat-row {
    grid-template-columns: 1fr;
  }
}

/* ── Language Toggle ── */

[data-lang="en"] { display: none; }
[data-lang="zh"] { display: block; }
span[data-lang="zh"],
a[data-lang="zh"],
strong[data-lang="zh"] { display: inline; }
.guide-links-grid[data-lang="zh"],
.related-links-grid[data-lang="zh"],
.journey-grid[data-lang="zh"],
.seo-faq-grid[data-lang="zh"],
.hero-stat-row[data-lang="zh"] { display: grid; }
.intro-keywords[data-lang="zh"],
.hero-actions[data-lang="zh"],
.section-pills[data-lang="zh"] { display: flex; }
[data-lang="en"].guide-links-grid,
[data-lang="en"].related-links-grid,
[data-lang="en"].journey-grid,
[data-lang="en"].seo-faq-grid,
[data-lang="en"].hero-stat-row,
[data-lang="en"].intro-keywords,
[data-lang="en"].section-pills,
[data-lang="en"].hero-actions { display: none; }

html.lang-en [data-lang="en"] { display: block; }
html.lang-en [data-lang="zh"] { display: none; }
html.lang-en span[data-lang="en"],
html.lang-en a[data-lang="en"],
html.lang-en strong[data-lang="en"] { display: inline; }
html.lang-en span[data-lang="zh"],
html.lang-en a[data-lang="zh"],
html.lang-en strong[data-lang="zh"] { display: none; }
html.lang-en .guide-links-grid[data-lang="en"],
html.lang-en .related-links-grid[data-lang="en"],
html.lang-en .journey-grid[data-lang="en"],
html.lang-en .seo-faq-grid[data-lang="en"],
html.lang-en .hero-stat-row[data-lang="en"] { display: grid; }
html.lang-en .intro-keywords[data-lang="en"],
html.lang-en .section-pills[data-lang="en"],
html.lang-en .hero-actions[data-lang="en"] { display: flex; }
html.lang-en .guide-links-grid[data-lang="zh"],
html.lang-en .related-links-grid[data-lang="zh"],
html.lang-en .journey-grid[data-lang="zh"],
html.lang-en .seo-faq-grid[data-lang="zh"],
html.lang-en .hero-stat-row[data-lang="zh"],
html.lang-en .intro-keywords[data-lang="zh"],
html.lang-en .section-pills[data-lang="zh"],
html.lang-en .hero-actions[data-lang="zh"] { display: none; }

.lang-float {
  position: fixed;
  bottom: 28px;
  right: 28px;
  z-index: 9999;
  display: inline-flex;
  align-items: center;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: 999px;
  overflow: hidden;
  font-family: var(--sans-en);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
  background: var(--nav-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 2px 16px rgba(0,0,0,.08);
}

.lang-float button {
  border: 0;
  background: transparent;
  padding: 8px 14px;
  cursor: pointer;
  color: var(--text-dim);
  font-family: inherit;
  font-size: inherit;
  font-weight: inherit;
  letter-spacing: inherit;
  text-transform: inherit;
  transition: background .2s, color .2s;
  white-space: nowrap;
}

.lang-float button:hover {
  color: var(--text-bright);
}

.lang-float button.active {
  background: var(--page-chip);
  color: var(--page-accent);
}

@media (max-width: 640px) {
  .lang-float {
    bottom: 18px;
    right: 18px;
    font-size: .68rem;
  }

  .lang-float button {
    padding: 7px 12px;
  }
}