:root {
  --ink: #292524;
  --muted: #78716c;
  --bg: #faf7f2;
  --card: #fff;
  --amber: #b45309;
  --line: #e7e0d6;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background:
    linear-gradient(#faf7f2, #faf7f2) padding-box;
  color: var(--ink);
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.75;
}
a { color: var(--amber); }
.bar {
  display: flex; justify-content: space-between; align-items: center;
  padding: 14px 8vw; background: #292524; color: #fff;
}
.brand { color: #fff; text-decoration: none; font-weight: 800; font-size: 20px; }
.bar nav { display: flex; gap: 16px; }
.bar nav a { color: #f5e6d3; text-decoration: none; }
.bar nav a.on { color: #fff; border-bottom: 2px solid #f59e0b; }
.flow { max-width: 860px; margin: 0 auto; padding: 28px 20px 72px; }
.hero h1 { font-size: 36px; line-height: 1.3; margin: 0 0 10px; }
.lead { font-size: 18px; }
.tags { display: flex; gap: 8px; flex-wrap: wrap; padding: 0; list-style: none; }
.tags li { background: #ffedd5; color: #9a3412; padding: 3px 10px; border-radius: 6px; font-size: 14px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--amber); color: #fff; text-decoration: none;
  padding: 12px 16px; font-weight: 700; border-radius: 6px;
}
.btn.ghost { background: #fff; color: var(--amber); border: 1px solid var(--amber); }
.btn-row { display: flex; flex-wrap: wrap; gap: 8px; }
.ladder { margin-top: 12px; }
.node {
  display: grid; grid-template-columns: 72px 1fr; gap: 8px;
  padding: 8px 0 20px; position: relative;
}
.node::before {
  content: "";
  position: absolute; left: 28px; top: 48px; bottom: 0;
  width: 2px; background: #fdba74;
}
.node:last-child::before { display: none; }
.num {
  width: 56px; height: 56px; border-radius: 50%;
  background: #fff7ed; color: var(--amber); border: 2px solid #fdba74;
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 20px;
}
h2 { font-size: 26px; margin: 0 0 8px; line-height: 1.35; }
.card { background: #fff; border: 1px solid var(--line); border-radius: 12px; padding: 8px 14px 14px; }
.ask article { background: #fff; border-left: 4px solid var(--amber); padding: 10px 14px; margin: 10px 0; }
.ask h3 { margin: 0 0 6px; font-size: 18px; }
footer { color: var(--muted); font-size: 13px; margin-top: 28px; }
table { width: 100%; border-collapse: collapse; background: #fff; }
th, td { border: 1px solid var(--line); padding: 10px; text-align: left; vertical-align: top; }
@media (max-width: 720px) {
  .bar { flex-direction: column; align-items: flex-start; gap: 8px; padding: 14px 16px; }
  .hero h1 { font-size: 28px; }
  .node { grid-template-columns: 56px 1fr; }
}