:root {
  --teal-ink: #082824;
  --teal: #0c3f3a;
  --teal-mid: #1a5c54;
  --cream: #f4ead8;
  --cream-deep: #e8d9be;
  --paper: #fbf6ec;
  --line: #cbb892;
  --text: #1a2a28;
  --muted: #4a5e5a;
  --accent: #c4a35a;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: auto; }
body {
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--paper);
  color: var(--text);
  line-height: 1.7;
}

.skip { position: absolute; left: -999px; }
a { color: var(--teal-mid); text-decoration: none; }
a:hover { text-decoration: underline; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--teal-ink);
  color: var(--cream);
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 20px 12px 248px;
  border-bottom: 3px solid var(--accent);
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  letter-spacing: 0.04em;
}
.brand svg { flex-shrink: 0; }

.rail {
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  width: 228px;
  background: var(--teal);
  color: var(--cream);
  padding: 88px 16px 24px;
  overflow: auto;
  border-right: 1px solid #0a2f2b;
}
.rail-label {
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--accent);
  margin-bottom: 14px;
  font-weight: 600;
}
.rail a {
  display: block;
  color: var(--cream);
  padding: 9px 12px;
  border-left: 3px solid transparent;
  margin-bottom: 4px;
}
.rail a:hover {
  background: var(--teal-mid);
  border-left-color: var(--accent);
  text-decoration: none;
}

.wrap {
  margin-left: 228px;
  padding: 28px 36px 64px;
  max-width: 1180px;
}

.hero {
  background: linear-gradient(160deg, var(--teal) 0%, #14564e 100%);
  color: var(--cream);
  padding: 36px 40px;
  border-radius: 6px 28px 6px 28px;
  margin-bottom: 32px;
}
.hero h1 {
  font-size: 30px;
  line-height: 1.35;
  margin-bottom: 16px;
  font-weight: 700;
}
.hero p { margin-bottom: 10px; max-width: 46em; }

.section { margin: 40px 0; }
.section > h2 {
  font-size: 22px;
  color: var(--teal);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--cream-deep);
}

.cards-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.card {
  background: var(--cream);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 18px 16px 20px;
}
.card svg { display: block; margin-bottom: 10px; }
.card h3 { font-size: 17px; color: var(--teal); margin-bottom: 8px; }
.card p { font-size: 15px; color: var(--muted); }

.steps-h {
  display: flex;
  gap: 0;
  background: var(--cream);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}
.step {
  flex: 1;
  padding: 18px 16px;
  border-right: 1px dashed var(--line);
  position: relative;
}
.step:last-child { border-right: none; }
.step .num {
  display: inline-block;
  width: 28px;
  height: 28px;
  line-height: 28px;
  text-align: center;
  background: var(--teal);
  color: var(--cream);
  border-radius: 50%;
  font-size: 14px;
  margin-bottom: 8px;
}
.step h3 { font-size: 16px; color: var(--teal-ink); margin-bottom: 6px; }
.step p { font-size: 14px; color: var(--muted); }

.pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.pair article {
  background: #fff;
  border: 1px solid var(--line);
  padding: 18px;
  border-radius: 8px;
}
.pair h3 { color: var(--teal); margin-bottom: 8px; }

table.compare {
  width: 100%;
  border-collapse: collapse;
  background: #fff;
}
table.compare th,
table.compare td {
  border: 1px solid var(--line);
  padding: 10px 12px;
  text-align: left;
  vertical-align: top;
  font-size: 14px;
}
table.compare th { background: var(--teal); color: var(--cream); }
table.compare tr:nth-child(even) td { background: var(--cream); }

.list-block {
  background: var(--cream);
  padding: 18px 22px;
  border-left: 6px solid var(--teal);
}
.list-block li { margin: 8px 0 8px 18px; }

.faq details {
  background: #fff;
  border: 1px solid var(--line);
  margin-bottom: 8px;
  padding: 10px 14px;
}
.faq summary { cursor: pointer; font-weight: 600; color: var(--teal); }
.faq details p { margin-top: 8px; color: var(--muted); }

footer {
  margin-left: 228px;
  background: var(--teal-ink);
  color: var(--cream);
  padding: 28px 36px 36px;
  font-size: 13px;
}
footer p { margin: 8px 0; max-width: 70em; }
footer .copy { color: var(--accent); margin-top: 16px; }

@media (max-width: 960px) {
  .rail { display: none; }
  .topbar, .wrap, footer { margin-left: 0; padding-left: 16px; padding-right: 16px; }
  .cards-3, .pair, .steps-h { grid-template-columns: 1fr; display: block; }
  .step { border-right: none; border-bottom: 1px dashed var(--line); }
}