:root {
  --green: #1f7a5c;
  --green-dark: #17614a;
  --ink: #1c2421;
  --muted: #5e6d68;
  --line: #e3ebe7;
  --bg: #f3f6f4;
  --card: #fff;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font: 16px/1.7 "PingFang SC", "Microsoft YaHei", sans-serif;
}
a { color: var(--green); text-decoration: none; }
a:hover { text-decoration: underline; }
.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  max-width: 960px;
  margin: 0 auto;
  padding: 16px 20px;
}
.brand { color: var(--ink); font-weight: 700; font-size: 18px; text-decoration: none; }
.nav { display: flex; flex-wrap: wrap; gap: 12px 18px; font-size: 14px; }
.nav a { color: var(--muted); text-decoration: none; white-space: nowrap; flex-shrink: 0; }
.nav a:hover { color: var(--green); }
.wrap { max-width: 960px; margin: 0 auto; padding: 8px 20px 48px; }
.hero {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 40px 32px;
}
.hero h1 { margin: 0 0 8px; font-size: 36px; line-height: 1.25; }
.lead { margin: 0 0 24px; color: var(--muted); font-size: 17px; max-width: 36em; }
.btn {
  display: inline-block;
  background: var(--green);
  color: #fff;
  text-decoration: none;
  padding: 12px 22px;
  border-radius: 8px;
  font-size: 16px;
  white-space: nowrap;
}
.btn:hover { background: var(--green-dark); text-decoration: none; }
h2 { margin: 36px 0 12px; font-size: 22px; }
.grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 16px 18px;
}
.card h3 { margin: 0 0 6px; font-size: 16px; }
.card p { margin: 0; color: var(--muted); font-size: 14px; }
.panel {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 20px 22px;
}
.panel p { margin: 8px 0; }
.license { display: block; width: min(100%, 720px); height: auto; margin-top: 12px; border: 1px solid var(--line); border-radius: 8px; background: #fff; }
.foot {
  max-width: 960px;
  margin: 0 auto;
  padding: 8px 20px 28px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.8;
}
.foot a { color: var(--muted); }
.doc { max-width: 720px; }
.doc h1 { font-size: 26px; margin: 12px 0 8px; }
.doc .meta { color: var(--muted); font-size: 13px; margin: 0; }
.doc h2 { font-size: 18px; }
.doc h3 { font-size: 16px; margin: 16px 0 6px; }
@media (max-width: 680px) {
  .top { align-items: flex-start; flex-direction: column; gap: 8px; }
  .hero { padding: 28px 20px; }
  .hero h1 { font-size: 28px; }
  .grid { grid-template-columns: 1fr; }
}