:root {
  --green: #7b9e87;
  --green-dark: #4f705a;
  --green-pale: #edf4ef;
  --cream: #f8f6f0;
  --paper: #fffefa;
  --ink: #25322a;
  --muted: #66736b;
  --line: #dfe7e1;
  --warm: #d9915b;
  --shadow: 0 18px 50px rgba(51, 76, 59, 0.09);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 12% 4%, rgba(123, 158, 135, 0.13), transparent 26rem),
    linear-gradient(180deg, #fbfcf9 0, var(--cream) 100%);
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.85;
}
a { color: var(--green-dark); }
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(123, 158, 135, 0.18);
  background: rgba(255, 254, 250, 0.92);
  backdrop-filter: blur(14px);
}
.nav {
  max-width: 1120px;
  height: 68px;
  margin: auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  font-size: 20px;
  font-weight: 800;
  text-decoration: none;
}
.brand-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  color: white;
  background: var(--green);
  border-radius: 11px;
}
.nav-links { display: flex; gap: 24px; }
.nav-links a { color: var(--muted); text-decoration: none; font-size: 14px; }
.nav-links a:hover { color: var(--green-dark); }
.hero {
  max-width: 1120px;
  margin: 0 auto;
  padding: 86px 24px 58px;
}
.eyebrow {
  color: var(--green-dark);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.14em;
}
.hero h1 {
  max-width: 800px;
  margin: 12px 0 18px;
  font-family: "Noto Serif SC", "Songti SC", serif;
  font-size: clamp(40px, 7vw, 72px);
  line-height: 1.14;
  letter-spacing: -0.04em;
}
.hero > p {
  max-width: 680px;
  color: var(--muted);
  font-size: 18px;
}
.topic-strip {
  max-width: 1120px;
  margin: 0 auto 32px;
  padding: 0 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.topic-strip span, .tag {
  padding: 7px 12px;
  color: var(--green-dark);
  background: var(--green-pale);
  border: 1px solid #d5e4d9;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 700;
}
.guide-grid {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px 96px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}
.guide-card {
  min-height: 260px;
  padding: 30px;
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: rgba(255, 254, 250, 0.88);
  box-shadow: var(--shadow);
  text-decoration: none;
  transition: transform 0.2s ease, border-color 0.2s ease;
}
.guide-card:hover { transform: translateY(-4px); border-color: var(--green); }
.guide-card h2 {
  margin: 18px 0 10px;
  color: var(--ink);
  font-family: "Noto Serif SC", "Songti SC", serif;
  font-size: 25px;
  line-height: 1.4;
}
.guide-card p { margin: 0; color: var(--muted); font-size: 15px; }
.guide-card .read { margin-top: auto; padding-top: 24px; font-weight: 800; }
.article-shell {
  max-width: 1120px;
  margin: 0 auto;
  padding: 42px 24px 96px;
  display: grid;
  grid-template-columns: minmax(0, 760px) 260px;
  gap: 72px;
  align-items: start;
}
.breadcrumb { margin-bottom: 32px; color: var(--muted); font-size: 13px; }
.breadcrumb a { text-decoration: none; }
.article-head { padding-bottom: 34px; border-bottom: 1px solid var(--line); }
.article-head h1 {
  margin: 14px 0 18px;
  font-family: "Noto Serif SC", "Songti SC", serif;
  font-size: clamp(34px, 6vw, 52px);
  line-height: 1.22;
  letter-spacing: -0.035em;
}
.lead { color: #4e5e54; font-size: 18px; }
.meta { color: var(--muted); font-size: 13px; }
.article-body { font-size: 16px; }
.article-body h2 {
  margin: 48px 0 16px;
  font-family: "Noto Serif SC", "Songti SC", serif;
  font-size: 26px;
  line-height: 1.4;
}
.article-body h3 { margin: 28px 0 8px; font-size: 18px; }
.article-body p { margin: 0 0 18px; }
.article-body ul, .article-body ol { padding-left: 1.35em; }
.article-body li { margin-bottom: 10px; }
.note, .warning, .product-box {
  margin: 28px 0;
  padding: 20px 22px;
  border-radius: 16px;
}
.note { border-left: 4px solid var(--green); background: var(--green-pale); }
.warning { border-left: 4px solid var(--warm); background: #fff5ec; }
.product-box {
  border: 1px solid #cfe0d3;
  background: linear-gradient(135deg, #f3f8f4, #fffefa);
}
.product-box strong { display: block; margin-bottom: 6px; }
.side-card {
  position: sticky;
  top: 96px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: rgba(255, 254, 250, 0.92);
}
.side-card strong { display: block; margin-bottom: 12px; }
.side-card a {
  display: block;
  padding: 9px 0;
  border-bottom: 1px solid var(--line);
  text-decoration: none;
  font-size: 14px;
}
.related { margin-top: 56px; padding-top: 34px; border-top: 1px solid var(--line); }
.related h2 { margin-top: 0; }
.related-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.related-grid a {
  min-height: 116px;
  padding: 16px;
  display: flex;
  align-items: flex-end;
  color: var(--ink);
  background: var(--green-pale);
  border-radius: 14px;
  font-weight: 700;
  line-height: 1.55;
  text-decoration: none;
}
.site-footer {
  padding: 42px 24px;
  color: #dae5dc;
  background: #314439;
  text-align: center;
  font-size: 13px;
}
.site-footer a { color: white; }

@media (max-width: 840px) {
  .guide-grid { grid-template-columns: 1fr; }
  .article-shell { grid-template-columns: 1fr; gap: 24px; }
  .side-card { position: static; }
}
@media (max-width: 620px) {
  .nav { height: 60px; padding: 0 18px; }
  .nav-links a:first-child { display: none; }
  .hero { padding: 58px 20px 38px; }
  .hero h1 { font-size: 42px; }
  .hero > p { font-size: 16px; }
  .topic-strip, .guide-grid, .article-shell { padding-left: 18px; padding-right: 18px; }
  .guide-card { min-height: 230px; padding: 24px; }
  .article-head h1 { font-size: 36px; }
  .lead { font-size: 17px; }
  .related-grid { grid-template-columns: 1fr; }
  .side-card { display: none; }
}