:root {
  --navy: #0b1830;
  --navy-2: #0f2547;
  --navy-3: #15304f;
  --cyan: #22c5dc;
  --cyan-soft: #5fd9ea;
  --ink: #1c2733;
  --muted: #5b6b7d;
  --line: #e3e9f0;
  --bg: #f6f8fb;
  --card: #ffffff;
  --radius: 14px;
  --maxw: 1160px;
  --shadow: 0 10px 30px rgba(11, 24, 48, 0.08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--navy-2); text-decoration: none; }
a:hover { color: var(--cyan); }
img { max-width: 100%; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 60;
  background: rgba(11, 24, 48, 0.94);
  backdrop-filter: saturate(160%) blur(8px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; color: #fff; }
.brand img { border-radius: 8px; }
.brand-name { font-weight: 700; font-size: 18px; letter-spacing: 0.5px; }
.brand-sub { color: var(--cyan-soft); font-size: 12px; border-left: 1px solid rgba(255,255,255,0.25); padding-left: 10px; }
.site-nav { display: flex; align-items: center; gap: 2px; }
.nav-item { position: relative; display: flex; align-items: center; }
.nav-item > a { display: inline-block; padding: 8px 14px; color: #d7e2f0; border-radius: 8px; font-size: 15px; }
.nav-item > a:hover { background: rgba(255,255,255,0.08); color: #fff; }
.nav-child-toggle { background: none; border: none; color: #9fb3c8; cursor: pointer; font-size: 16px; padding: 4px 8px; }
.nav-child {
  display: none; position: absolute; top: 100%; left: 0; min-width: 168px;
  background: #0f2547; border: 1px solid rgba(255,255,255,0.1); border-radius: 10px;
  padding: 6px; box-shadow: var(--shadow); list-style: none; margin: 0; z-index: 70;
}
.nav-has-child.open .nav-child { display: block; }
.nav-child li a { display: block; padding: 8px 12px; color: #d7e2f0; border-radius: 8px; font-size: 14px; }
.nav-child li a:hover { background: rgba(255,255,255,0.08); color: #fff; }
.nav-toggle { display: none; flex-direction: column; gap: 4px; background: none; border: none; cursor: pointer; padding: 8px; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: #fff; }

/* ---------- Floating capsule ---------- */
.floating-capsule {
  position: fixed; right: 18px; top: 50%; transform: translateY(-50%);
  display: flex; flex-direction: column; gap: 10px; z-index: 80;
}
.cap-btn {
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 2px;
  width: 52px; height: 52px; border-radius: 26px; border: 1px solid rgba(255,255,255,0.18);
  background: linear-gradient(160deg, var(--navy-2), var(--navy)); color: #fff; cursor: pointer;
  box-shadow: var(--shadow); font-size: 11px; transition: transform .15s, background .15s;
}
.cap-btn:hover { transform: translateY(-2px); background: linear-gradient(160deg, var(--cyan), #1aa6bd); }
.cap-btn span { line-height: 1; }

/* ---------- WeChat modal ---------- */
.wechat-modal { position: fixed; inset: 0; z-index: 100; display: flex; align-items: center; justify-content: center; }
.wechat-modal[hidden] { display: none; }
.wechat-modal-mask { position: absolute; inset: 0; background: rgba(6, 14, 28, 0.66); }
.wechat-modal-box {
  position: relative; background: #fff; border-radius: 16px; padding: 14px;
  box-shadow: 0 30px 80px rgba(0,0,0,0.4); max-width: 92vw; max-height: 92vh;
}
.wechat-modal-box img { display: block; width: auto; height: auto; max-width: 90vw; max-height: 84vh; border-radius: 10px; }
.wechat-close {
  position: absolute; top: -14px; right: -14px; width: 34px; height: 34px; border-radius: 50%;
  border: none; background: #fff; color: #333; font-size: 20px; cursor: pointer; box-shadow: var(--shadow);
}

/* ---------- Breadcrumb ---------- */
.breadcrumb { padding: 18px 0 0; padding-left: var(--h2-inset, 0); flex: 0 0 100%; }
.breadcrumb ol { list-style: none; display: flex; flex-wrap: wrap; gap: 6px; margin: 0; padding: 0; font-size: 13px; color: var(--muted); }
.breadcrumb li { display: inline-flex; align-items: center; }
.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--cyan); }
.breadcrumb .sep { margin: 0 6px; color: #b6c2d0; }
.breadcrumb .current span { color: var(--ink); font-weight: 600; }

/* ---------- Article / product layout ---------- */
.article-layout { display: flex; flex-wrap: wrap; gap: 40px; align-items: flex-start; padding-top: 10px; padding-bottom: 60px; --h2-inset: 16px; }
.article-main { flex: 1 1 auto; max-width: 760px; min-width: 0; }
.toc-aside { flex: 0 0 240px; position: sticky; top: 84px; max-height: calc(100vh - 110px); overflow-y: auto; }
.toc-inner { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 18px; }
.toc-head { margin: 0 0 10px; font-size: 13px; color: var(--muted); letter-spacing: 1px; text-transform: uppercase; }
.toc-inner ul { list-style: none; margin: 0; padding: 0; }
.toc-inner li a { display: block; padding: 4px 0; color: var(--muted); font-size: 14px; border-left: 2px solid transparent; padding-left: 10px; }
.toc-inner li a:hover, .toc-inner li.active a { color: var(--cyan); border-left-color: var(--cyan); }
.toc-inner li.lvl-3 a { padding-left: 22px; font-size: 13px; }

.article-title { font-size: 30px; line-height: 1.3; margin: 6px 0 18px; color: var(--navy); }
.summary-block { background: linear-gradient(135deg, #eaf7fb, #f3f8ff); border-left: 4px solid var(--cyan); border-radius: 0 12px 12px 0; padding: 16px 18px; margin: 0 0 16px; color: #243747; font-size: 16px; }
.keyword-line { font-size: 14px; color: var(--muted); margin: 0 0 6px; }
.keyword-line strong { color: var(--navy-2); }
.update-line { font-size: 13px; color: #93a2b3; margin: 0 0 22px; }

.article-body { font-size: 16px; color: #25323f; }
.article-body h2 { font-size: 23px; margin: 34px 0 14px; color: var(--navy); border-left: 4px solid var(--cyan); padding-left: 12px; }
.article-body h3 { font-size: 19px; margin: 26px 0 12px; color: var(--navy-2); }
.article-body p { margin: 0 0 16px; }
.article-body ul, .article-body ol { margin: 0 0 16px; padding-left: 22px; }
.article-body li { margin: 6px 0; }
.article-body blockquote { background: #f1f5f9; border-left: 4px solid var(--navy-3); margin: 18px 0; padding: 14px 18px; border-radius: 0 10px 10px 0; color: #314453; }
.article-body blockquote p { margin: 0; }
.article-body table.data { width: 100%; border-collapse: collapse; margin: 18px 0; font-size: 15px; background: #fff; border-radius: 10px; overflow: hidden; box-shadow: var(--shadow); }
.article-body table.data th, .article-body table.data td { border: 1px solid var(--line); padding: 10px 12px; text-align: left; }
.article-body table.data th { background: var(--navy-2); color: #fff; font-weight: 600; }
.article-body table.data tr:nth-child(even) td { background: #f7fafc; }
.article-body code { background: #eef2f7; padding: 1px 6px; border-radius: 5px; font-size: 14px; }
.article-body pre { background: #0f2547; color: #d7e2f0; padding: 14px; border-radius: 10px; overflow-x: auto; }

.product-desc { font-size: 16px; color: #314453; margin: 0 0 22px; background: #fff; border: 1px solid var(--line); border-radius: 10px; padding: 14px 16px; }

/* ---------- FAQ ---------- */
.faq-block { margin-top: 36px; }
.faq-title, .related-title { font-size: 22px; color: var(--navy); border-left: 4px solid var(--cyan); padding-left: 12px; }
.faq-block details { background: #fff; border: 1px solid var(--line); border-radius: 10px; margin: 10px 0; padding: 0 16px; }
.faq-block summary { cursor: pointer; font-weight: 600; color: var(--navy-2); padding: 14px 0; list-style: none; }
.faq-block summary::-webkit-details-marker { display: none; }
.faq-block summary::before { content: "Q"; display: inline-block; width: 22px; height: 22px; line-height: 22px; text-align: center; background: var(--cyan); color: #042; border-radius: 6px; font-size: 12px; margin-right: 10px; font-weight: 700; }
.faq-a { padding: 0 0 14px 32px; color: #314453; }

/* ---------- Related ---------- */
.related-block { margin-top: 30px; }
.related-list { list-style: none; padding: 0; margin: 12px 0 0; }
.related-list li { padding: 10px 0; border-bottom: 1px dashed var(--line); }
.related-why { color: var(--muted); font-size: 14px; margin-left: 6px; }

/* ---------- List / category ---------- */
.list-layout { display: flex; flex-wrap: wrap; gap: 40px; align-items: flex-start; padding-top: 22px; padding-bottom: 60px; --h2-inset: 16px; }
.cat-side { flex: 0 0 220px; position: sticky; top: 84px; }
.cat-side-title { font-size: 13px; color: var(--muted); letter-spacing: 1px; text-transform: uppercase; margin: 0 0 10px; }
.category-list { list-style: none; margin: 0; padding: 0; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; background: #fff; }
.category-list li a { display: block; padding: 12px 16px; color: var(--ink); border-bottom: 1px solid var(--line); }
.category-list li:last-child a { border-bottom: none; }
.category-list li a:hover { background: #eaf7fb; color: var(--cyan); padding-left: 22px; transition: padding .15s; }
.category-list li.active a { background: var(--navy-2); color: #fff; }
.cat-content { flex: 1 1 auto; min-width: 0; }
.cat-title { font-size: 28px; color: var(--navy); margin: 4px 0 10px; }
.cat-intro { color: var(--muted); margin: 0 0 24px; }
.item-list { list-style: none; padding: 0; margin: 0; }
.item-row { background: #fff; border: 1px solid var(--line); border-radius: 12px; padding: 18px 20px; margin: 0 0 14px; transition: box-shadow .15s, transform .15s; }
.item-row:hover { box-shadow: var(--shadow); transform: translateY(-2px); }
.item-row-title { font-size: 19px; font-weight: 700; color: var(--navy); }
.item-row-summary { color: #3a4a59; margin: 8px 0 6px; }
.item-row-meta { font-size: 13px; color: var(--cyan); background: #eaf7fb; padding: 2px 10px; border-radius: 20px; }

/* ---------- Home ---------- */
.hero { background: radial-gradient(1200px 500px at 80% -10%, rgba(34,197,220,0.25), transparent), linear-gradient(160deg, var(--navy), var(--navy-2)); color: #fff; padding: 70px 0 80px; }
.hero-inner { display: flex; align-items: center; gap: 50px; }
.hero-eyebrow { color: var(--cyan-soft); letter-spacing: 2px; font-size: 13px; margin: 0 0 12px; }
.hero-title { font-size: 40px; line-height: 1.25; margin: 0 0 18px; }
.hero-sub { color: #c7d6e6; max-width: 560px; font-size: 16px; }
.hero-actions { margin: 26px 0; display: flex; gap: 14px; }
.btn { display: inline-block; padding: 12px 22px; border-radius: 30px; font-weight: 600; cursor: pointer; border: none; font-size: 15px; }
.btn-primary { background: var(--cyan); color: #042; }
.btn-primary:hover { background: var(--cyan-soft); color: #042; }
.btn-ghost { background: transparent; border: 1px solid rgba(255,255,255,0.4); color: #fff; }
.btn-ghost:hover { background: rgba(255,255,255,0.1); color: #fff; }
.hero-stats { list-style: none; display: flex; gap: 30px; padding: 0; margin: 30px 0 0; }
.hero-stats li { display: flex; flex-direction: column; }
.hero-stats strong { font-size: 22px; color: var(--cyan-soft); }
.hero-stats span { font-size: 13px; color: #9fb3c8; }
.hero-visual { position: relative; width: 280px; height: 280px; flex: 0 0 280px; }
.ring { position: absolute; border-radius: 50%; border: 1px solid rgba(34,197,220,0.4); }
.ring-1 { inset: 0; }
.ring-2 { inset: 36px; border-color: rgba(34,197,220,0.6); }
.ring-3 { inset: 72px; border-color: rgba(34,197,220,0.8); }
.core { position: absolute; inset: 104px; background: linear-gradient(160deg, var(--cyan), #1aa6bd); border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 30px; font-weight: 800; color: #042; box-shadow: 0 0 40px rgba(34,197,220,0.5); }

.section { padding: 60px 0; }
.section-alt { background: #eef3f9; }
.section-title { font-size: 28px; color: var(--navy); margin: 0 0 8px; text-align: center; }
.section-lead { text-align: center; color: var(--muted); margin: 0 auto 34px; max-width: 680px; }
.tree-grid, .scene-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 18px; }
.tree-card, .scene-card { background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 22px; transition: transform .15s, box-shadow .15s; }
.tree-card:hover, .scene-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.tree-card h3, .scene-card h3 { margin: 0 0 10px; color: var(--navy-2); font-size: 18px; }
.tree-card p, .scene-card p { color: #46586a; font-size: 14px; margin: 0 0 12px; }
.tree-go { color: var(--cyan); font-weight: 600; font-size: 14px; }
.home-articles { list-style: none; padding: 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 18px; margin: 0; }
.home-articles li { background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 20px; }
.home-articles h3 { margin: 0 0 8px; color: var(--navy); font-size: 17px; }
.home-articles p { color: #46586a; font-size: 14px; margin: 0 0 10px; }
.home-article-cat { font-size: 12px; color: var(--cyan); background: #eaf7fb; padding: 2px 10px; border-radius: 20px; }
.home-more { text-align: center; margin-top: 26px; }
.section-cta { background: linear-gradient(160deg, var(--navy-2), var(--navy)); color: #fff; }
.cta-inner { display: flex; align-items: center; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.cta-inner h2 { margin: 0 0 6px; }
.cta-inner p { color: #c7d6e6; margin: 0; }

/* ---------- Page (about) ---------- */
.page-wrap { padding: 30px 24px 60px; --h2-inset: 48px; }
.page-title { font-size: 30px; color: var(--navy); margin: 10px 0 20px; }
.page-body { background: #fff; border: 1px solid var(--line); border-radius: 14px; padding: 28px 32px; max-width: 860px; }
.page-body h2 { color: var(--navy-2); border-left: 4px solid var(--cyan); padding-left: 12px; margin-top: 26px; }
.page-body table.data { width: 100%; border-collapse: collapse; margin: 16px 0; }
.page-body table.data th, .page-body table.data td { border: 1px solid var(--line); padding: 10px 12px; text-align: left; }
.page-body table.data th { background: var(--navy-2); color: #fff; }

/* ---------- 404 ---------- */
.notfound { text-align: center; padding: 100px 0; }
.notfound h1 { font-size: 72px; color: var(--cyan); margin: 0; }
.notfound p { color: var(--muted); margin: 10px 0 24px; }

/* ---------- Footer ---------- */
.site-footer { background: var(--navy); color: #c7d6e6; margin-top: 40px; }
.footer-inner { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 30px; padding: 46px 0 30px; }
.footer-brand { display: flex; gap: 14px; align-items: flex-start; }
.footer-brand strong { color: #fff; display: block; font-size: 16px; }
.footer-brand p { margin: 4px 0 0; font-size: 14px; }
.footer-col h4 { color: #fff; font-size: 15px; margin: 0 0 14px; }
.footer-col ul { list-style: none; padding: 0; margin: 0; }
.footer-col li { margin: 8px 0; }
.footer-col a { color: #9fb3c8; font-size: 14px; }
.footer-col a:hover { color: var(--cyan); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.08); padding: 16px 0; }
.footer-bottom .container { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-size: 13px; color: #7e93a8; }

/* ---------- Responsive ---------- */
@media (max-width: 980px) {
  .article-layout { flex-direction: column; }
  .toc-aside { display: none; }
  .list-layout { flex-direction: column; }
  .cat-side { position: static; flex: none; width: 100%; }
  .category-list { display: flex; flex-wrap: wrap; }
  .category-list li { flex: 1 1 auto; }
  .category-list li a { border-bottom: none; border-right: 1px solid var(--line); }
  .hero-inner { flex-direction: column; text-align: center; }
  .hero-visual { display: none; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 720px) {
  .nav-toggle { display: flex; }
  .site-nav {
    display: none; position: absolute; top: 64px; left: 0; right: 0;
    flex-direction: column; gap: 0; background: #0f2547; padding: 8px; border-top: 1px solid rgba(255,255,255,0.1);
  }
  .site-nav.open { display: flex; }
  .nav-item { width: 100%; flex-direction: column; align-items: stretch; }
  .nav-item > a { display: block; }
  .nav-child-toggle { position: absolute; right: 8px; top: 4px; }
  .nav-child { position: static; box-shadow: none; border: none; background: rgba(255,255,255,0.04); margin: 0 12px; }
  .nav-has-child.open .nav-child { display: block; }
  .hero-title { font-size: 30px; }
  .hero-stats { flex-wrap: wrap; gap: 18px; }
  .footer-inner { grid-template-columns: 1fr; }
  .floating-capsule { right: 10px; }
  .cap-btn { width: 46px; height: 46px; }
}