:root {
  --ink: #134e4a;
  --muted: #3f6f6b;
  --bg: #f3fbfa;
  --card: #ffffff;
  --teal: #0f766e;
  --line: #cce8e4;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Georgia", "Songti SC", "Microsoft YaHei", serif;
  line-height: 1.85;
}
a { color: #0f766e; }
.essay {
  display: grid;
  grid-template-columns: minmax(0, 760px) 300px;
  gap: 36px;
  max-width: 1120px;
  margin: 0 auto;
  padding: 24px 20px 80px;
}
.brandline { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; margin-bottom: 18px; font-family: "Segoe UI", "Microsoft YaHei", sans-serif; }
.brand { font-weight: 800; font-size: 20px; color: var(--ink); text-decoration: none; }
.brandline nav { display: flex; gap: 14px; }
.brandline nav a { text-decoration: none; color: var(--muted); }
.brandline nav a.on { color: var(--teal); font-weight: 700; }
h1 { font-size: 36px; line-height: 1.35; margin: 0 0 12px; }
.lead { font-size: 18px; }
.marks { padding: 0; margin: 0 0 12px; list-style: none; display: flex; flex-wrap: wrap; gap: 8px; font-family: "Segoe UI", "Microsoft YaHei", sans-serif; font-size: 14px; }
.marks li { background: #d7f3ef; padding: 2px 8px; }
.btn {
  display: inline-block; background: var(--teal); color: #fff; text-decoration: none;
  padding: 10px 16px; font-family: "Segoe UI", "Microsoft YaHei", sans-serif; font-weight: 700;
}
.btn.quiet { background: #fff; color: var(--teal); border: 1px solid var(--teal); }
.row { display: flex; flex-wrap: wrap; gap: 8px; margin: 10px 0 18px; }
h2 { font-size: 26px; line-height: 1.4; margin: 26px 0 8px; }
.qblock { border-top: 1px dashed var(--line); padding-top: 8px; }
.rail {
  position: sticky; top: 18px; align-self: start;
  background: var(--card); border: 1px solid var(--line); padding: 16px;
  font-family: "Segoe UI", "Microsoft YaHei", sans-serif; line-height: 1.6;
}
.rail h2 { font-size: 18px; margin-top: 0; }
.faq article { margin: 14px 0; }
.faq h3 { font-family: "Segoe UI", "Microsoft YaHei", sans-serif; font-size: 18px; margin: 0 0 4px; }
footer { grid-column: 1 / -1; color: var(--muted); font-size: 13px; font-family: "Segoe UI", "Microsoft YaHei", sans-serif; }
table { width: 100%; border-collapse: collapse; background: #fff; font-family: "Segoe UI", "Microsoft YaHei", sans-serif; }
th, td { border-bottom: 1px solid var(--line); text-align: left; padding: 8px; vertical-align: top; }
@media (max-width: 900px) {
  .essay { grid-template-columns: 1fr; }
  .rail { position: static; }
  h1 { font-size: 30px; }
}