:root {
  --paper: #fbfaf6;
  --ink: #222522;
  --muted: #686f67;
  --line: #dedbd2;
  --green: #235a45;
  --gold: #b58b3b;
  --coral: #c96651;
  --soft: #eef2eb;
  --white: #ffffff;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", Arial, sans-serif;
  line-height: 1.82;
}

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

.page {
  max-width: 920px;
  margin: 0 auto;
  padding: 44px 22px 86px;
}

.top-nav,
.bottom-nav {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 42px;
  color: var(--green);
  font-size: 15px;
  font-weight: 700;
}

.bottom-nav {
  margin-top: 58px;
  margin-bottom: 0;
  padding-top: 28px;
  border-top: 1px solid var(--line);
}

.chapter-kicker {
  margin: 0 0 12px;
  color: var(--gold);
  font-size: 15px;
  font-weight: 800;
}

h1 {
  margin: 0 0 24px;
  font-size: clamp(38px, 6vw, 70px);
  line-height: 1.08;
  letter-spacing: 0;
}

h2 {
  margin: 46px 0 18px;
  font-size: clamp(26px, 4vw, 38px);
  line-height: 1.25;
}

h3 {
  margin: 34px 0 12px;
  font-size: 23px;
  line-height: 1.35;
}

p {
  margin: 0 0 18px;
  font-size: 18px;
}

.lead {
  margin-bottom: 30px;
  color: #394139;
  font-size: 23px;
  line-height: 1.72;
}

.chapter-brief {
  display: grid;
  gap: 10px;
  margin: 26px 0 36px;
  padding: 22px 24px;
  border: 1px solid rgba(35, 90, 69, 0.18);
  border-radius: 8px;
  background: #f4f8f2;
}

.chapter-brief p {
  margin: 0;
  color: #334139;
  font-size: 16px;
  line-height: 1.7;
}

.chapter-brief strong {
  color: var(--green);
}

.chapter-bridge {
  margin: 34px 0 0;
  padding: 22px 24px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  color: #465047;
  background: rgba(255, 255, 255, 0.52);
}

.chapter-bridge p {
  margin: 0;
  font-size: 17px;
}

.quote {
  margin: 32px 0;
  padding: 26px 28px;
  border-left: 5px solid var(--gold);
  background: var(--soft);
  color: #26352d;
  font-size: 21px;
  line-height: 1.7;
  font-weight: 700;
}

.action-box {
  margin: 30px 0;
  padding: 24px 26px;
  border: 1px solid rgba(181, 139, 59, 0.35);
  border-radius: 8px;
  background: #fffaf0;
}

.action-box strong {
  color: var(--green);
}

.checklist {
  display: grid;
  gap: 12px;
  margin: 26px 0;
}

.check {
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
}

.check b {
  display: block;
  margin-bottom: 6px;
  color: var(--green);
}

.check span {
  display: block;
  color: var(--muted);
  font-size: 15px;
}

@media (max-width: 640px) {
  .top-nav,
  .bottom-nav {
    flex-direction: column;
  }

  p {
    font-size: 16px;
  }

  .lead {
    font-size: 19px;
  }
}