:root {
  --bg: #f6f1e8;
  --card: #fffdf8;
  --line: #e8dfd2;
  --text: #1f1b16;
  --sub: #8a8174;
  --body: #4a433a;
  --brand: #c4652a;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background:
    radial-gradient(1400px 700px at 18% -10%, #fff8ee 0%, transparent 52%),
    var(--bg);
}

.shell {
  min-height: 100vh;
  padding: 40px 32px 64px;
}

.book {
  width: min(720px, 100%);
  margin: 0 auto;
}

.top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 28px;
}

.brand {
  font-size: 22px;
  font-weight: 600;
  color: inherit;
  text-decoration: none;
}

.nav a {
  color: var(--sub);
  font-size: 14px;
  text-decoration: none;
  margin-left: 16px;
}

.nav a:hover {
  color: var(--brand);
}

h1 {
  font-size: 28px;
  line-height: 36px;
  margin: 0 0 8px;
}

.meta {
  color: var(--sub);
  font-size: 14px;
  margin: 0 0 32px;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 28px 28px 8px;
}

h2 {
  font-size: 16px;
  margin: 8px 0 10px;
}

p,
li {
  color: var(--body);
  font-size: 16px;
  line-height: 26px;
}

ul {
  margin: 0 0 20px;
  padding-left: 1.2em;
}

.empty {
  text-align: center;
  padding: 48px 16px 56px;
}

.empty h2 {
  font-size: 18px;
  margin: 0 0 8px;
}

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

.pkg {
  display: none;
  padding-bottom: 24px;
}

.pkg.show {
  display: block;
}

.btn {
  display: inline-block;
  height: 48px;
  line-height: 48px;
  padding: 0 22px;
  border-radius: 20px;
  background: var(--brand);
  color: #fff;
  text-decoration: none;
  font-size: 16px;
}

.btn[hidden] {
  display: none;
}

.foot {
  margin-top: 24px;
  color: var(--sub);
  font-size: 12px;
}

.beian {
  margin-top: 16px;
  text-align: center;
  font-size: 12px;
}

.beian a {
  color: var(--sub);
}