:root {
  --teal: #0d7377;
  --teal-d: #095456;
  --wash: #f4f7f6;
  --card: #ffffff;
  --ink: #1d2a2c;
  --line: #cfd8d6;
  --aside: #e6f2f1;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--wash);
  color: var(--ink);
  font-family: "Helvetica Neue", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.72;
}

.bar {
  background: var(--teal);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  height: 58px;
}
.bar .brand { color: #fff; text-decoration: none; font-weight: 700; font-size: 18px; }
.bar nav a {
  color: #d7f3f2;
  text-decoration: none;
  margin-left: 22px;
  font-size: 14px;
  padding-bottom: 4px;
  border-bottom: 2px solid transparent;
}
.bar nav a.now { color: #fff; border-bottom-color: #fff; }

.frame {
  width: min(1120px, calc(100% - 32px));
  margin: 24px auto 0;
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 28px;
}

.toc {
  position: sticky;
  top: 16px;
  background: var(--aside);
  padding: 16px 14px;
  border-left: 4px solid var(--teal);
  font-size: 14px;
  height: max-content;
}
.toc strong { display: block; margin-bottom: 8px; color: var(--teal-d); }
.toc a { display: block; color: var(--teal-d); text-decoration: none; padding: 5px 0; }

.lead {
  background: var(--card);
  padding: 28px 28px 22px;
  border: 1px solid var(--line);
}
.lead h1 { margin: 0 0 12px; font-size: 28px; color: var(--teal-d); }
.actions { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 16px; }
.act, .act2 {
  display: inline-block;
  text-decoration: none;
  padding: 11px 18px;
  font-size: 15px;
}
.act { background: var(--teal); color: #fff; }
.act2 { background: #fff; color: var(--teal); border: 1px solid var(--teal); }

.sec {
  background: var(--card);
  margin-top: 16px;
  padding: 24px 28px;
  border: 1px solid var(--line);
}
.sec h2 {
  margin: 0 0 12px;
  font-size: 20px;
  color: var(--teal);
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
}

.diff {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}
.diff th, .diff td { border: 1px solid var(--line); padding: 9px 10px; text-align: left; }
.diff th { background: var(--aside); color: var(--teal-d); }

.q { margin: 14px 0 0; }
.q h3 { font-size: 16px; margin: 0 0 6px; }
.q p { margin: 0 0 8px; }

.base {
  background: var(--teal-d);
  color: #dceceb;
  margin-top: 40px;
  padding: 26px 28px;
  font-size: 13px;
}
.base a { color: #b7ece8; margin-right: 16px; }

@media (max-width: 860px) {
  .frame { grid-template-columns: 1fr; }
  .toc { position: static; }
  .bar { flex-wrap: wrap; height: auto; padding: 12px 16px; }
}