:root {
  --maxw: 720px;
  --ink: #1a1a1a;
  --muted: #6b6b6b;
  --line: #e5e5e5;
}
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  color: var(--ink);
  background: #fff;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 17px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--ink); }
a:hover { text-decoration: underline; }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

.site-header { border-bottom: 1px solid var(--line); }
.site-header .container {
  display: flex; align-items: center; justify-content: space-between;
  padding-top: 18px; padding-bottom: 18px;
}
.brand { font-weight: 600; font-size: 1.05rem; text-decoration: none; }
.nav { display: flex; gap: 1.25rem; }
.nav a { text-decoration: none; font-size: 0.95rem; }

main { padding: 2.5rem 0 3rem; }

.hero h1 { font-size: 1.8rem; margin: 0 0 0.75rem; }
.hero p { color: var(--muted); margin: 0; }

.section-title {
  font-size: 1.1rem; font-weight: 600;
  margin: 2.5rem 0 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--line);
}

.cards { display: grid; gap: 1rem; list-style: none; margin: 0; padding: 0; }
.card {
  display: block;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 1.1rem 1.25rem;
  text-decoration: none;
  color: var(--ink);
}
.card:hover { border-color: #b5b5b5; box-shadow: 0 1px 4px rgba(0,0,0,.04); text-decoration: none; }
.card h2 { font-size: 1.1rem; margin: 0 0 0.4rem; }
.card .summary { color: var(--muted); font-size: 0.95rem; margin: 0 0 0.6rem; }
.card .meta { color: var(--muted); font-size: 0.82rem; }

.article h1 { font-size: 1.6rem; line-height: 1.3; margin: 0 0 0.4rem; }
.article .meta { color: var(--muted); font-size: 0.88rem; margin-bottom: 1.5rem; }
.article p { margin: 0 0 1.1rem; }
.back { display: inline-block; margin-top: 2rem; text-decoration: none; font-size: 0.92rem; }

.about h1 { font-size: 1.6rem; margin: 0 0 1rem; }
.about p { margin: 0 0 1rem; }

.site-footer {
  border-top: 1px solid var(--line);
  padding: 1.25rem 0 2rem;
  color: var(--muted);
  font-size: 0.82rem;
}
.site-footer p { margin: 0.25rem 0; }
.site-footer a { color: var(--muted); text-decoration: none; }
.site-footer .beian-icon {
  width: 14px;
  height: 14px;
  vertical-align: -2px;
  margin-right: 4px;
}

@media (max-width: 540px) {
  body { font-size: 16px; }
  .site-header .container { flex-direction: column; gap: 0.5rem; align-items: flex-start; }
  .nav { gap: 1rem; }
}