:root {
  --paper: #f4f0e6;
  --paper-2: #e9e3d6;
  --card: #fffcf6;
  --ink: #1c1d1a;
  --soft: #3e423c;
  --muted: #5e5a52;
  --line: #d9d2c4;
  --cyan: #0b6570;
  --cyan-2: #14828e;
  --heat: #c53622;
  --heat-dark: #9d2918;
  --ok: #1d6b40;
  --shadow: 0 16px 40px rgba(28, 29, 26, 0.08);
  --sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", "Segoe UI", sans-serif;
  --mono: "Cascadia Mono", "Sarasa Gothic SC", Consolas, "Microsoft YaHei", monospace;
  --max: 1120px;
  --header: 68px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(900px 420px at -10% -10%, rgba(11, 101, 112, 0.08), transparent 60%),
    radial-gradient(700px 380px at 110% 0%, rgba(197, 54, 34, 0.06), transparent 55%),
    var(--paper);
  font-family: var(--sans);
  font-size: 16.5px;
  line-height: 1.75;
}
img { max-width: 100%; }
a { color: var(--cyan); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--heat); }
button, input, select, textarea { font: inherit; color: inherit; }
::selection { background: #f3c7bf; }

.skip {
  position: absolute;
  left: 12px;
  top: -40px;
  background: var(--ink);
  color: white;
  padding: 8px 12px;
  z-index: 20;
}
.skip:focus { top: 12px; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  height: var(--header);
  display: flex;
  align-items: center;
  background: rgba(28, 29, 26, 0.96);
  color: #f6f3ec;
  border-bottom: 3px solid var(--cyan-2);
  backdrop-filter: blur(10px);
}
.topbar .inner, .wrap { width: min(var(--max), calc(100% - 40px)); margin: 0 auto; }
.topbar .inner { display: flex; align-items: center; gap: 28px; width: min(1180px, calc(100% - 32px)); }
.brand { display: flex; align-items: center; gap: 10px; color: inherit; text-decoration: none; }
.brand b { font-size: 18px; letter-spacing: 0.08em; }
.brand small { display: block; color: #b7b2a6; font-family: var(--mono); font-size: 10px; letter-spacing: 0.14em; }
.mark {
  width: 28px; height: 28px; border: 1.5px solid #f6f3ec; position: relative; flex: none;
}
.mark:before, .mark:after {
  content: ""; position: absolute; background: #3ec6d4;
}
.mark:before { width: 8px; height: 1.5px; left: -1px; top: -1px; box-shadow: 21px 0 #3ec6d4, 0 21px #3ec6d4, 21px 21px #3ec6d4; }
.mark:after { width: 1.5px; height: 8px; left: -1px; top: -1px; box-shadow: 21px 0 #3ec6d4, 0 21px #3ec6d4, 21px 21px #3ec6d4; }

.nav-links { display: flex; align-items: center; gap: 4px; margin-left: auto; }
.nav-links > a, .drop > button {
  color: #f6f3ec; text-decoration: none; background: none; border: 0; padding: 8px 10px; cursor: pointer;
}
.nav-links > a.btn-primary { background: var(--heat); border: 1px solid var(--heat); color: white; }
.nav-links > a[aria-current="page"], .drop[data-current="true"] > button { color: #8fe3ea; }
.drop { position: relative; }
.menu {
  display: none; position: absolute; top: 100%; left: 0; min-width: 220px;
  background: #fffcf6; color: var(--ink); padding: 8px; border: 1px solid var(--line); box-shadow: var(--shadow);
}
.menu a { display: block; padding: 8px 10px; color: var(--ink); text-decoration: none; }
.menu a:hover, .menu a[aria-current="page"] { background: var(--paper-2); color: var(--ink); }
.drop:hover .menu, .drop:focus-within .menu { display: block; }
.nav-toggle { display: none; margin-left: auto; background: transparent; color: #f6f3ec; border: 1px solid #6d6a62; padding: 6px 10px; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 11px 16px; border: 1px solid var(--ink); background: transparent; color: var(--ink);
  text-decoration: none; cursor: pointer; line-height: 1.2;
}
.btn:hover { background: var(--ink); color: #f6f3ec; }
.btn-primary { background: var(--heat); border-color: var(--heat); color: white; }
.btn-primary:hover { background: var(--heat-dark); color: white; }
.btn-light { background: transparent; border-color: #f6f3ec; color: #f6f3ec; }
.btn-light:hover { background: #f6f3ec; color: var(--ink); }
.topbar .btn { padding: 8px 12px; }

.hero { padding: 64px 0 28px; }
.hero-grid, .split { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr); gap: 42px; align-items: center; }
.hero-grid > *, .split > *, .grid-2 > *, .grid-3 > *, .grid-4 > *, .price-grid > *, .contact-box > * { min-width: 0; }
.kicker, .sec-kicker {
  font-family: var(--mono); font-size: 12px; letter-spacing: 0.12em; color: var(--cyan); margin: 0 0 10px;
}
h1 { font-size: clamp(34px, 5vw, 54px); line-height: 1.18; margin: 0 0 16px; letter-spacing: -0.03em; font-weight: 700; }
h2 { font-size: clamp(26px, 3vw, 34px); line-height: 1.25; margin: 0 0 12px; letter-spacing: -0.02em; }
h3 { font-size: 20px; line-height: 1.35; margin: 0 0 8px; }
.lede { font-size: 18px; color: var(--soft); margin: 0 0 22px; }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin: 18px 0; }
.fine { color: var(--muted); font-size: 14px; }

.stage { position: relative; min-height: 460px; }
.sheet {
  position: relative; background: var(--card); border: 1px solid var(--line); min-height: 430px;
  box-shadow: var(--shadow); padding: 36px 28px; max-width: 100%;
}
.sheet:before {
  content: ""; position: absolute; inset: 12px; pointer-events: none;
  background:
    linear-gradient(var(--ink), var(--ink)) 0 0 / 16px 1px no-repeat,
    linear-gradient(var(--ink), var(--ink)) 0 0 / 1px 16px no-repeat,
    linear-gradient(var(--ink), var(--ink)) 100% 0 / 16px 1px no-repeat,
    linear-gradient(var(--ink), var(--ink)) 100% 0 / 1px 16px no-repeat,
    linear-gradient(var(--ink), var(--ink)) 0 100% / 16px 1px no-repeat,
    linear-gradient(var(--ink), var(--ink)) 0 100% / 1px 16px no-repeat,
    linear-gradient(var(--ink), var(--ink)) 100% 100% / 16px 1px no-repeat,
    linear-gradient(var(--ink), var(--ink)) 100% 100% / 1px 16px no-repeat;
}
.sheet-meta { font-family: var(--mono); font-size: 11px; color: var(--muted); display: flex; justify-content: space-between; gap: 8px; flex-wrap: wrap; margin-bottom: 18px; }
.label-face {
  width: 100%; max-width: 300px; margin: 8px auto 0; background: white; color: #1c1d1a;
  border: 1px solid #1c1d1a; padding: 12px 14px 10px; box-shadow: 5px 5px 0 rgba(28, 29, 26, 0.12);
}
.label-face .t { font-weight: 700; text-align: center; font-size: 18px; line-height: 1.25; }
.label-face .rule { height: 1px; background: #1c1d1a; margin: 6px 0 8px; }
.label-face .small { font-size: 12px; line-height: 1.45; }
.label-face .row2 { display: flex; justify-content: space-between; gap: 8px; }
.bars {
  height: 42px; margin-top: 8px;
  background: repeating-linear-gradient(90deg, #1c1d1a 0 1px, transparent 1px 3px, #1c1d1a 3px 6px, transparent 6px 8px, #1c1d1a 8px 9px, transparent 9px 12px);
}
.var { color: var(--cyan); font-family: var(--mono); font-size: 12px; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.chip {
  background: var(--ink); color: #f6f3ec; font-size: 12px; padding: 5px 8px; font-family: var(--mono);
}
.chip.hot { background: var(--heat); }
.chip.cool { background: var(--cyan); }

.facts { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); margin: 10px 0 20px; }
.facts div { padding: 18px 16px; border-right: 1px solid var(--line); }
.facts div:last-child { border-right: 0; }
.facts b { display: block; font-size: 18px; letter-spacing: -0.02em; }
.facts span { color: var(--muted); font-size: 13px; }

.section { padding: 64px 0; }
.section-h { max-width: 720px; margin-bottom: 28px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 14px; }
.card, .price, .case, .guide {
  background: var(--card); border: 1px solid var(--line); padding: 18px 18px 16px; height: 100%;
}
.card h3, .case h3, .guide h3 { font-size: 18px; }
.card p, .case p, .guide p { margin: 0; color: var(--soft); }
.card .more, .case .more { display: inline-block; margin-top: 12px; }
.num { font-family: var(--mono); color: var(--cyan); font-size: 12px; letter-spacing: 0.08em; }

.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; counter-reset: step; }
.step { padding: 8px 18px 8px 0; border-top: 2px solid var(--ink); }
.step b { display: block; margin: 8px 0 4px; }
.step span { color: var(--muted); font-family: var(--mono); font-size: 12px; }

.band { background: var(--ink); color: #f6f3ec; }
.band a { color: #8fe3ea; }
.band .card { background: #262824; border-color: #3a3d38; color: #f6f3ec; }
.band .card p { color: #d9d3c6; }

.price-grid { display: grid; grid-template-columns: 1fr 1.08fr 1fr; gap: 16px; align-items: stretch; }
.price { display: flex; flex-direction: column; gap: 8px; position: relative; }
.price .cost { font-size: 40px; letter-spacing: -0.04em; line-height: 1; margin: 6px 0; }
.price .cost small { font-size: 15px; letter-spacing: 0; color: var(--muted); margin-left: 4px; }
.price ul { margin: 8px 0 16px; padding: 0; list-style: none; }
.price li { padding: 6px 0 6px 18px; position: relative; border-top: 1px solid var(--line); }
.price li:before { content: ""; width: 6px; height: 6px; background: var(--cyan); position: absolute; left: 0; top: 14px; }
.price .btn { margin-top: auto; }
.price.featured { background: #1c1d1a; color: #f6f3ec; border-color: #1c1d1a; }
.price.featured li { border-color: #3a3d38; }
.price.featured .cost small, .price.featured .fine { color: #c9c3b6; }
.price.featured li:before { border-color: #3ec6d4; }
.ribbon {
  position: absolute; top: 12px; right: 12px; background: var(--heat); color: white;
  font-size: 12px; padding: 3px 8px;
}

table { width: 100%; border-collapse: collapse; background: var(--card); }
th, td { text-align: left; padding: 12px 14px; border-bottom: 1px solid var(--line); vertical-align: top; }
th { font-size: 14px; background: #efeadd; }
.table-wrap { overflow-x: auto; border: 1px solid var(--line); }

.faq details { background: var(--card); border: 1px solid var(--line); border-bottom: 0; padding: 0 16px; }
.faq details:last-child { border-bottom: 1px solid var(--line); }
.faq summary { cursor: pointer; padding: 14px 0; font-weight: 700; }
.faq details p { margin: 0 0 14px; color: var(--soft); }

.crumbs { font-size: 13px; color: var(--muted); margin-bottom: 14px; }
.crumbs a { color: var(--muted); }
.page-hero { padding: 42px 0 10px; }
.page-hero h1 { font-size: clamp(32px, 4vw, 46px); }
.prose { max-width: 760px; }
.prose h2 { margin-top: 36px; font-size: 28px; }
.prose h3 { margin-top: 22px; }
.prose ul, .prose ol { padding-left: 1.2em; }
.limit, .note {
  border-left: 3px solid var(--cyan); background: rgba(255, 252, 246, 0.7); padding: 12px 14px; margin: 18px 0;
}
.limit b { display: block; }
.related { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 18px; }
.related a { background: var(--card); border: 1px solid var(--line); padding: 6px 10px; text-decoration: none; color: var(--ink); }
.related a:hover { border-color: var(--ink); }

.cta-band {
  display: flex; justify-content: space-between; gap: 20px; align-items: center;
  background: var(--ink); color: #f6f3ec; padding: 28px; margin: 28px 0 10px;
}
.cta-band h2 { color: white; font-size: 28px; margin: 0 0 6px; }
.cta-band p { margin: 0; color: #d9d3c6; }

.form { display: grid; gap: 12px; }
.form label { display: grid; gap: 6px; font-size: 14px; }
.form input, .form select, .form textarea {
  width: 100%; background: white; border: 1px solid var(--line); padding: 10px 12px;
}
.form input:focus, .form select:focus, .form textarea:focus { outline: 2px solid var(--cyan); border-color: var(--cyan); }
.contact-box { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.wechat {
  background: var(--card); border: 1px solid var(--line); padding: 18px;
}
.wechat code { font-family: var(--mono); font-size: 22px; }

.footer { border-top: 1px solid var(--line); padding: 36px 0 80px; margin-top: 20px; color: var(--soft); }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 22px; }
.footer a { color: var(--soft); text-decoration: none; display: inline-block; margin: 3px 0; }
.footer a:hover { color: var(--heat); }
.footer h3 { font-size: 14px; letter-spacing: 0.08em; }
.legal { margin-top: 22px; color: var(--muted); font-size: 13px; }

.mobile-bar { display: none; }

.ba { display: grid; gap: 12px; }
.ba-switch { display: flex; gap: 8px; }
.ba input { position: absolute; opacity: 0; pointer-events: none; }
.ba-switch label { border: 1px solid var(--ink); padding: 6px 10px; cursor: pointer; }
#ba-after:checked ~ .ba-switch label[for="ba-after"],
#ba-before:checked ~ .ba-switch label[for="ba-before"] { background: var(--ink); color: #f6f3ec; }
.pane-after { display: none; }
#ba-after:checked ~ .pane-before { display: none; }
#ba-after:checked ~ .pane-after { display: block; }
.ghost { color: #8a8478; filter: blur(0.2px); }

@media (max-width: 980px) {
  .hero-grid, .split, .facts, .steps, .grid-3, .grid-4, .price-grid, .footer-grid, .contact-box { grid-template-columns: 1fr 1fr; }
  .facts div:nth-child(odd) { border-bottom: 1px solid var(--line); }
  .steps { grid-template-columns: 1fr 1fr; gap: 16px; }
}
@media (max-width: 860px) {
  .nav-toggle { display: inline-flex; }
  .nav-links {
    display: none; position: absolute; top: var(--header); left: 0; right: 0;
    background: #1c1d1a; flex-direction: column; align-items: stretch; padding: 8px 16px 16px; gap: 0;
  }
  .nav-links.open { display: flex; }
  .menu { position: static; display: block; background: transparent; border: 0; box-shadow: none; min-width: 0; padding: 0 0 8px 12px; }
  .menu a { color: #f6f3ec; }
  .menu a:hover { background: #2a2c28; color: white; }
  .topbar .btn { display: none; }
  .hero { padding-top: 32px; }
  .hero-grid, .split, .grid-2, .grid-3, .grid-4, .facts, .price-grid, .footer-grid, .contact-box, .steps { grid-template-columns: 1fr; }
  .facts div { border-right: 0; border-bottom: 1px solid var(--line); }
  .stage { min-height: 0; }
  .sheet { min-height: 0; padding: 22px 14px; }
  .cta-band { flex-direction: column; align-items: flex-start; }
  .mobile-bar {
    display: flex; position: fixed; left: 0; right: 0; bottom: 0; z-index: 25;
    background: #1c1d1a; padding: 10px 14px; gap: 8px;
  }
  .mobile-bar .btn { flex: 1; }
  body { padding-bottom: 64px; }
  .wrap, .topbar .inner { width: min(var(--max), calc(100% - 28px)); }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}