:root {
  --bg: #ffffff;
  --bg-soft: #f7f7f5;
  --bg-brand: #e6f1fb;
  --text: #1f1f1d;
  --text-2: #5f5e5a;
  --text-3: #888780;
  --line: rgba(0, 0, 0, 0.10);
  --line-2: rgba(0, 0, 0, 0.18);
  --brand: #185fa5;
  --brand-dark: #0c447c;
  --accent: #0f6e56;
  --warn: #854f0b;
  --warn-bg: #faeeda;
  --radius: 12px;
  --radius-sm: 8px;
  --max: 1080px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  margin: 0;
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.01em;
}

h1 { font-size: 34px; }
h2 { font-size: 26px; }
h3 { font-size: 19px; }
h4 { font-size: 16px; }

p { margin: 0 0 1rem; }

a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

img { max-width: 100%; display: block; }

.container {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 24px;
}

.skip-link {
  position: absolute;
  left: -9999px;
}
.skip-link:focus {
  left: 24px;
  top: 12px;
  z-index: 200;
  background: #fff;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line-2);
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 24px;
  height: 64px;
}

.logo {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
  white-space: nowrap;
}
.logo:hover { text-decoration: none; }
.logo span {
  font-size: 12px;
  font-weight: 400;
  color: var(--text-3);
}

.nav {
  display: flex;
  gap: 4px;
  margin-left: auto;
  align-items: center;
}
.nav a {
  padding: 8px 12px;
  font-size: 14px;
  color: var(--text-2);
  border-radius: var(--radius-sm);
}
.nav a:hover {
  background: var(--bg-soft);
  color: var(--text);
  text-decoration: none;
}
.nav a.is-active {
  color: var(--brand);
  background: var(--bg-brand);
}

.nav-toggle {
  display: none;
  margin-left: auto;
  background: none;
  border: 1px solid var(--line-2);
  border-radius: var(--radius-sm);
  padding: 6px 12px;
  font-size: 14px;
  color: var(--text);
  cursor: pointer;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 500;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background .15s, color .15s;
}
.btn:hover { text-decoration: none; }
.btn-primary {
  background: var(--brand);
  color: #fff;
}
.btn-primary:hover { background: var(--brand-dark); }
.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--line-2);
}
.btn-ghost:hover { background: var(--bg-soft); }
.btn-sm { padding: 7px 14px; font-size: 14px; }

/* Hero */
.hero {
  padding: 72px 0 56px;
  background: linear-gradient(180deg, var(--bg-brand) 0%, var(--bg) 100%);
  border-bottom: 1px solid var(--line);
}
.hero h1 { max-width: 20ch; margin-bottom: 20px; }
.hero-lead {
  font-size: 18px;
  color: var(--text-2);
  max-width: 60ch;
  margin-bottom: 28px;
}
.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 36px;
}

.eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 500;
  color: var(--brand);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 14px;
  margin-bottom: 20px;
}

/* Stats */
.stat-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 16px;
  margin-top: 8px;
}
.stat {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
}
.stat-num {
  font-size: 28px;
  font-weight: 600;
  color: var(--brand);
  line-height: 1.2;
}
.stat-label {
  font-size: 13px;
  color: var(--text-2);
  margin-top: 4px;
}
.stat-note {
  font-size: 12px;
  color: var(--text-3);
  margin-top: 10px;
}

/* Sections */
.section { padding: 64px 0; }
.section-soft { background: var(--bg-soft); }
.section-head { margin-bottom: 32px; max-width: 70ch; }
.section-head h2 { margin-bottom: 12px; }
.section-head p {
  color: var(--text-2);
  font-size: 17px;
  margin: 0;
}

/* Grids */
.grid { display: grid; gap: 16px; }
.grid-2 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.grid-4 { grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); }

.card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
}
.card h3 { margin-bottom: 10px; font-size: 17px; }
.card p { color: var(--text-2); font-size: 15px; margin: 0; }
.card p + p { margin-top: 10px; }

.card-link {
  display: block;
  color: inherit;
  transition: border-color .15s, transform .15s;
}
.card-link:hover {
  text-decoration: none;
  border-color: var(--line-2);
  transform: translateY(-2px);
}
.card-link .card-arrow {
  display: block;
  margin-top: 14px;
  font-size: 14px;
  color: var(--brand);
}

/* Badge */
.badge {
  display: inline-block;
  font-size: 12px;
  padding: 2px 10px;
  border-radius: 999px;
  background: var(--bg-soft);
  color: var(--text-2);
  border: 1px solid var(--line);
  margin-right: 6px;
}
.badge-brand { background: var(--bg-brand); color: var(--brand-dark); border-color: transparent; }

/* Table */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
}
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
  min-width: 640px;
}
th, td {
  padding: 14px 16px;
  text-align: left;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
thead th {
  background: var(--bg-soft);
  font-weight: 600;
  font-size: 14px;
  color: var(--text-2);
  white-space: nowrap;
}
tbody tr:last-child td { border-bottom: none; }
td strong { font-weight: 600; }

/* Prose */
.prose { max-width: 74ch; }
.prose h2 {
  margin: 48px 0 16px;
  padding-top: 8px;
}
.prose h3 { margin: 32px 0 12px; }
.prose p { color: var(--text-2); }
.prose ul, .prose ol { color: var(--text-2); padding-left: 22px; }
.prose li { margin-bottom: 8px; }
.prose strong { color: var(--text); font-weight: 600; }

.callout {
  background: var(--bg-brand);
  border-left: 3px solid var(--brand);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  margin: 24px 0;
}
.callout p { margin: 0; color: var(--text); font-size: 15px; }
.callout-warn {
  background: var(--warn-bg);
  border-left-color: var(--warn);
}

/* FAQ */
.faq-item {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  margin-bottom: 10px;
  overflow: hidden;
}
.faq-item summary {
  cursor: pointer;
  padding: 16px 20px;
  font-size: 16px;
  font-weight: 500;
  list-style: none;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: flex-start;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  color: var(--text-3);
  font-size: 20px;
  line-height: 1;
  flex-shrink: 0;
}
.faq-item[open] summary::after { content: "–"; }
.faq-item .faq-body {
  padding: 0 20px 18px;
  color: var(--text-2);
  font-size: 15px;
}
.faq-item .faq-body p:last-child { margin-bottom: 0; }

/* TOC */
.toc {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 24px;
  background: var(--bg-soft);
  margin-bottom: 32px;
}
.toc-title { font-size: 14px; font-weight: 600; margin-bottom: 10px; }
.toc ol { margin: 0; padding-left: 20px; font-size: 15px; }
.toc li { margin-bottom: 6px; }

/* Breadcrumb */
.breadcrumb {
  font-size: 13px;
  color: var(--text-3);
  padding: 16px 0 0;
}
.breadcrumb a { color: var(--text-2); }
.breadcrumb span { margin: 0 6px; }

/* CTA band */
.cta-band {
  background: var(--bg-brand);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 40px;
  text-align: center;
}
.cta-band h2 { margin-bottom: 12px; }
.cta-band p {
  color: var(--text-2);
  max-width: 56ch;
  margin: 0 auto 24px;
}
.cta-band .contact-line {
  font-size: 15px;
  color: var(--text-2);
  margin-top: 20px;
}
.cta-band .contact-line strong { color: var(--text); }

/* City chips */
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  display: inline-block;
  font-size: 14px;
  padding: 6px 14px;
  border-radius: 999px;
  background: #fff;
  border: 1px solid var(--line);
  color: var(--text-2);
}
.chip:hover { border-color: var(--line-2); color: var(--text); text-decoration: none; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--line);
  background: var(--bg-soft);
  padding: 48px 0 32px;
  font-size: 14px;
  color: var(--text-2);
}
.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
  margin-bottom: 32px;
}
.footer-grid h4 {
  font-size: 14px;
  margin-bottom: 12px;
  color: var(--text);
}
.footer-grid ul { list-style: none; margin: 0; padding: 0; }
.footer-grid li { margin-bottom: 8px; }
.footer-grid a { color: var(--text-2); }
.footer-grid a:hover { color: var(--brand); }

.disclaimer {
  border-top: 1px solid var(--line);
  padding-top: 20px;
  font-size: 13px;
  color: var(--text-3);
  line-height: 1.7;
}
.disclaimer p { margin: 0 0 8px; }

/* Mobile */
@media (max-width: 860px) {
  h1 { font-size: 27px; }
  h2 { font-size: 22px; }
  .hero { padding: 48px 0 40px; }
  .hero-lead { font-size: 16px; }
  .section { padding: 48px 0; }
  .nav-toggle { display: block; }
  .nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: #fff;
    border-bottom: 1px solid var(--line);
    padding: 8px;
  }
  .nav.is-open { display: flex; }
  .nav a { padding: 12px 16px; }
  .header-inner { position: relative; }
  .cta-band { padding: 28px 20px; }
  .stat-num { font-size: 24px; }
}