/* 根站：左侧固定导航 + 主栏，森林绿 / 米色，卡片两列 */
:root {
  --forest: #1B4332;
  --forest-deep: #0B2419;
  --forest-mid: #2D6A4F;
  --beige: #F4F1EA;
  --paper: #FFFDF8;
  --ink: #1C1917;
  --muted: #5C574E;
  --line: #D8D0C4;
  --rail: 240px;
}

* { box-sizing: border-box; }

html { scroll-behavior: auto; }

body {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--beige);
  color: var(--ink);
  line-height: 1.7;
}

a { color: inherit; text-decoration: none; }

.rail {
  position: fixed;
  inset: 0 auto 0 0;
  width: var(--rail);
  background: var(--forest);
  color: #F4F1EA;
  padding: 22px 18px 28px;
  overflow-y: auto;
  z-index: 20;
}

.rail-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 22px;
  padding-bottom: 16px;
  border-bottom: 1px solid rgba(244, 241, 234, 0.18);
}

.rail-brand svg {
  flex: 0 0 36px;
  width: 36px;
  height: 36px;
}

.rail-brand strong {
  font-size: 15px;
  letter-spacing: 0.04em;
}

.rail nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.rail nav a {
  display: block;
  padding: 8px 10px;
  border-radius: 6px;
  font-size: 13px;
  color: rgba(244, 241, 234, 0.86);
}

.rail nav a:hover,
.rail nav a:focus {
  background: var(--forest-mid);
  color: #fff;
}

.workspace {
  margin-left: var(--rail);
  min-height: 100vh;
}

.topstrip {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 36px;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
}

.topstrip svg { width: 22px; height: 22px; }
.topstrip span { font-weight: 650; font-size: 15px; }

.hero {
  padding: 36px 36px 20px;
  max-width: 980px;
}

.hero h1 {
  margin: 0 0 16px;
  font-size: 30px;
  line-height: 1.35;
  color: var(--forest);
}

.hero p {
  margin: 0 0 12px;
  color: var(--muted);
  max-width: 42em;
}

.panel {
  padding: 8px 36px 28px;
  max-width: 980px;
}

.panel h2 {
  margin: 28px 0 12px;
  font-size: 22px;
  color: var(--forest);
  line-height: 1.4;
}

.panel > p {
  margin: 0 0 14px;
  color: var(--muted);
}

.card-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 16px 16px 14px;
}

.card:hover { border-color: var(--forest-mid); }

.card svg {
  width: 28px;
  height: 28px;
  display: block;
  margin-bottom: 8px;
  color: var(--forest);
}

.card h3 {
  margin: 0 0 8px;
  font-size: 16px;
  color: var(--forest-deep);
}

.card p {
  margin: 0 0 8px;
  font-size: 14px;
  color: var(--muted);
}

.card p:last-child { margin-bottom: 0; }

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 12px 0 8px;
}

.step {
  background: var(--paper);
  border: 1px solid var(--line);
  border-top: 4px solid var(--forest);
  padding: 14px;
}

.step b {
  display: block;
  color: var(--forest);
  font-size: 13px;
  margin-bottom: 6px;
}

.step p {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
}

table.compare {
  width: 100%;
  border-collapse: collapse;
  background: var(--paper);
  font-size: 14px;
  margin: 8px 0 12px;
}

table.compare th,
table.compare td {
  border: 1px solid var(--line);
  padding: 10px 12px;
  text-align: left;
  vertical-align: top;
}

table.compare th {
  background: var(--forest);
  color: #F4F1EA;
  font-weight: 600;
}

table.compare tr:hover td { background: #EFE8DC; }

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.split article {
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 16px;
}

.split h3 {
  margin: 0 0 8px;
  font-size: 16px;
  color: var(--forest);
}

.split p { margin: 0 0 8px; color: var(--muted); font-size: 14px; }
.split p:last-child { margin-bottom: 0; }

.faq details {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 14px;
  margin-bottom: 8px;
}

.faq details[open] { border-color: var(--forest-mid); }

.faq summary {
  cursor: pointer;
  font-weight: 650;
  color: var(--forest-deep);
}

.faq details p {
  margin: 8px 0 4px;
  color: var(--muted);
  font-size: 14px;
}

.site-foot {
  margin-left: var(--rail);
  background: var(--forest-deep);
  color: #E6E0D4;
  padding: 28px 36px 36px;
  font-size: 13px;
}

.site-foot p { margin: 0 0 8px; max-width: 52em; }
.site-foot p:last-child { margin-bottom: 0; }

@media (max-width: 960px) {
  .rail {
    position: relative;
    width: 100%;
    height: auto;
    inset: auto;
  }
  .workspace,
  .site-foot { margin-left: 0; }
  .rail nav { flex-direction: row; flex-wrap: wrap; }
  .card-grid,
  .split,
  .steps { grid-template-columns: 1fr; }
  .hero,
  .panel,
  .topstrip { padding-left: 18px; padding-right: 18px; }
}