:root {
  --paper: #f4f3ee;
  --paper-2: #eceae2;
  --ink: #17201c;
  --ink-soft: #4d5751;
  --rule: #cfcdc2;
  --pitch: #1f4d3a;
  --pitch-deep: #14332a;
  --lime: #a9c65d;
  --radius: 3px;
  --maxw: 1240px;
}

* { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: 0.01em;
}

img { max-width: 100%; height: auto; display: block; }

a { color: var(--pitch); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.01em;
  margin: 0 0 0.5em;
}

h1 { font-size: clamp(1.7rem, 3.4vw, 2.5rem); }
h2 { font-size: clamp(1.3rem, 2.2vw, 1.65rem); }
h3 { font-size: 1.12rem; }

p { margin: 0 0 1.1em; }

.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 20px;
}

/* ---------- header ---------- */
.site-head {
  border-bottom: 2px solid var(--ink);
  background: var(--paper);
  position: sticky;
  top: 0;
  z-index: 40;
}

.head-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  min-height: 68px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.12rem;
  color: var(--ink);
  letter-spacing: 0.06em;
  flex: 0 0 auto;
}
.brand:hover { text-decoration: none; }
.brand img { width: 34px; height: 34px; border-radius: 4px; }

.nav-main { margin-left: auto; }

.nav-main ul {
  display: flex;
  align-items: center;
  gap: 26px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-main a {
  color: var(--ink);
  font-size: 0.95rem;
  padding: 8px 2px;
  border-bottom: 2px solid transparent;
}
.nav-main a:hover { text-decoration: none; border-bottom-color: var(--pitch); }
.nav-main a.is-active { border-bottom-color: var(--lime); }

.menu-btn {
  display: none;
  margin-left: auto;
  background: none;
  border: 1px solid var(--ink);
  border-radius: var(--radius);
  color: var(--ink);
  font: inherit;
  font-size: 0.9rem;
  padding: 8px 14px;
  min-height: 44px;
}

/* ---------- home: brand band ---------- */
.band {
  background: var(--pitch-deep);
  color: #f2f4ee;
  padding: 12px 0;
  border-bottom: 1px solid #0d251d;
}
.band-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 30px;
  font-size: 0.84rem;
  letter-spacing: 0.05em;
  color: #cbd7c9;
}
.band-inner strong { color: var(--lime); font-weight: 700; }

/* ---------- home hero ---------- */
.hero {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 0;
  align-items: stretch;
  border-bottom: 2px solid var(--ink);
}
.hero-copy {
  padding: 54px 44px 54px 0;
  align-self: center;
}
.hero-kicker {
  font-size: 0.8rem;
  letter-spacing: 0.2em;
  color: var(--pitch);
  font-weight: 700;
  margin-bottom: 14px;
}
.hero h1 { margin-bottom: 16px; }
.hero p.lead {
  font-size: 1.02rem;
  color: var(--ink-soft);
  max-width: 46ch;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 22px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 10px 22px;
  border-radius: var(--radius);
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.04em;
  border: 1px solid var(--pitch-deep);
  background: var(--pitch-deep);
  color: #f6f7f1;
}
.btn:hover { text-decoration: none; background: var(--pitch); }
.btn.ghost {
  background: transparent;
  color: var(--pitch-deep);
  border-color: var(--pitch-deep);
}
.btn.ghost:hover { background: var(--paper-2); }

.hero-figure { position: relative; border-left: 2px solid var(--ink); }
.hero-figure img { height: 100%; width: 100%; object-fit: cover; }

/* ---------- sections ---------- */
section { padding: 52px 0; }
section + section { border-top: 1px solid var(--rule); }

.sec-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 24px;
  border-bottom: 1px solid var(--rule);
  padding-bottom: 10px;
}
.sec-head h2 { margin: 0; }
.sec-head span { font-size: 0.85rem; color: var(--ink-soft); }

/* stats row */
.stat-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}
.stat {
  background: var(--paper);
  padding: 20px 18px;
}
.stat b {
  display: block;
  font-size: 1.55rem;
  letter-spacing: -0.02em;
  color: var(--pitch-deep);
}
.stat span { font-size: 0.85rem; color: var(--ink-soft); }

/* two column feature */
.feature-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 34px;
  align-items: center;
}
.feature-split figure { margin: 0; }
.feature-split img { border: 1px solid var(--rule); }

/* category tiles (asymmetric) */
.cat-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 1px;
  background: var(--ink);
  border: 1px solid var(--ink);
}
.cat-cell {
  background: var(--paper);
  padding: 26px 22px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.cat-cell:first-child { background: var(--paper-2); }
.cat-cell h3 { margin: 0; }
.cat-cell p { font-size: 0.92rem; color: var(--ink-soft); margin: 0; }
.cat-cell .more { font-size: 0.85rem; font-weight: 700; margin-top: auto; }

/* lead article */
.lead-story {
  display: grid;
  grid-template-columns: 1.25fr 1fr;
  gap: 0;
  border: 1px solid var(--ink);
}
.lead-story img { height: 100%; object-fit: cover; }
.lead-body { padding: 30px 28px; background: #fff; }
.lead-body .meta { font-size: 0.82rem; color: var(--ink-soft); margin-bottom: 10px; }
.lead-body h3 { font-size: 1.35rem; }

/* article list rows */
.rows { list-style: none; margin: 0; padding: 0; }
.rows li {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 18px;
  padding: 16px 0;
  border-bottom: 1px solid var(--rule);
  align-items: start;
}
.rows li:first-child { padding-top: 0; }
.rows time { font-size: 0.82rem; color: var(--ink-soft); letter-spacing: 0.04em; }
.rows h3 { margin: 0 0 4px; font-size: 1.03rem; }
.rows p { margin: 0; font-size: 0.9rem; color: var(--ink-soft); }

/* three-up cards, intentionally offset */
.card-offset {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.card-offset article {
  border-top: 3px solid var(--pitch);
  padding-top: 14px;
}
.card-offset article:nth-child(2) { margin-top: 28px; }
.card-offset img { margin-bottom: 12px; border: 1px solid var(--rule); }
.card-offset h3 { font-size: 1rem; }
.card-offset p { font-size: 0.9rem; color: var(--ink-soft); }

/* checklist */
.check-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px 30px;
}
.check-list li {
  padding-left: 22px;
  position: relative;
  font-size: 0.95rem;
}
.check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 9px;
  height: 9px;
  background: var(--lime);
  border: 1px solid var(--pitch-deep);
}

/* FAQ */
.faq { border-top: 1px solid var(--rule); }
.faq details {
  border-bottom: 1px solid var(--rule);
  padding: 14px 0;
}
.faq summary {
  cursor: pointer;
  font-weight: 700;
  list-style: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq details p { margin: 10px 0 0; color: var(--ink-soft); }

/* CTA */
.cta-panel {
  background: var(--pitch-deep);
  color: #eef2e8;
  padding: 46px 40px;
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 30px;
  align-items: center;
  border-radius: var(--radius);
}
.cta-panel h2 { color: #fff; }
.cta-panel p { color: #c6d3c6; margin: 0; }
.cta-panel .btn {
  background: var(--lime);
  color: var(--pitch-deep);
  border-color: var(--lime);
  justify-self: end;
}
.cta-panel .btn:hover { background: #bcd477; }

/* ---------- inner pages ---------- */
.page-head {
  padding: 40px 0 26px;
  border-bottom: 2px solid var(--ink);
}
.page-head p { color: var(--ink-soft); max-width: 70ch; margin: 6px 0 0; }

.breadcrumb {
  font-size: 0.82rem;
  color: var(--ink-soft);
  padding: 14px 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.breadcrumb a { color: var(--ink-soft); }
.breadcrumb span[aria-current] { color: var(--ink); }

.layout-article {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 44px;
  padding: 8px 0 54px;
}

.layout-article .article-body { min-width: 0; }

.article-meta {
  font-size: 0.84rem;
  color: var(--ink-soft);
  display: flex;
  flex-wrap: wrap;
  gap: 6px 16px;
  padding: 10px 0 20px;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 22px;
}

.article-body h2 {
  margin-top: 1.9em;
  padding-top: 0.4em;
  border-top: 1px solid var(--rule);
}
.article-body h3 { margin-top: 1.5em; }
.article-body ul, .article-body ol { padding-left: 1.3em; margin: 0 0 1.2em; }
.article-body li { margin-bottom: 0.45em; }
.article-body blockquote {
  margin: 1.6em 0;
  padding: 14px 20px;
  border-left: 4px solid var(--lime);
  background: var(--paper-2);
  color: var(--ink-soft);
}
.article-body figure { margin: 1.8em 0; }
.article-body figcaption {
  font-size: 0.82rem;
  color: var(--ink-soft);
  padding-top: 8px;
}

.figure-inline img { border: 1px solid var(--rule); }

.figure-right {
  float: right;
  width: 46%;
  margin: 0 0 1.2em 1.8em;
}

.figure-wide img { width: 100%; }

.article-aside {
  border-left: 1px solid var(--rule);
  padding-left: 24px;
  align-self: start;
  position: sticky;
  top: 92px;
}
.aside-title {
  font-size: 0.82rem;
  letter-spacing: 0.16em;
  font-weight: 700;
  color: var(--pitch);
  margin: 0 0 14px;
  text-transform: none;
}
.related { list-style: none; margin: 0 0 26px; padding: 0; }
.related li {
  padding: 12px 0;
  border-bottom: 1px dashed var(--rule);
}
.related li:first-child { padding-top: 0; }
.related a { font-size: 0.94rem; font-weight: 600; color: var(--ink); }
.related small { display: block; color: var(--ink-soft); font-size: 0.78rem; padding-top: 4px; }

.back-cat {
  display: inline-block;
  font-size: 0.88rem;
  font-weight: 700;
  margin-top: 10px;
}

/* category pages */
.cat-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.cat-list li {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 24px;
  padding: 24px 0;
  border-bottom: 1px solid var(--rule);
  align-items: start;
}
.cat-list img { border: 1px solid var(--rule); }
.cat-list h3 { margin: 0 0 6px; font-size: 1.1rem; }
.cat-list .meta { font-size: 0.82rem; color: var(--ink-soft); margin-bottom: 6px; }
.cat-list p { margin: 0 0 8px; font-size: 0.93rem; color: var(--ink-soft); }

/* ---------- footer ---------- */
.site-foot {
  border-top: 2px solid var(--ink);
  background: var(--paper-2);
  padding: 40px 0 26px;
  margin-top: 10px;
}
.foot-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 30px;
  padding-bottom: 26px;
}
.foot-grid h4 {
  font-size: 0.86rem;
  letter-spacing: 0.12em;
  margin-bottom: 10px;
}
.foot-grid p { font-size: 0.9rem; color: var(--ink-soft); margin: 0 0 8px; }
.foot-links { list-style: none; margin: 0; padding: 0; }
.foot-links li { margin-bottom: 6px; font-size: 0.9rem; }
.legal {
  border-top: 1px solid var(--rule);
  padding-top: 16px;
  font-size: 0.8rem;
  color: var(--ink-soft);
  display: flex;
  flex-wrap: wrap;
  gap: 6px 22px;
}

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; }
  .hero-copy { padding: 34px 0 28px; }
  .hero-figure { border-left: 0; border-top: 2px solid var(--ink); }
  .cat-grid { grid-template-columns: 1fr; }
  .lead-story { grid-template-columns: 1fr; }
  .layout-article { grid-template-columns: 1fr; gap: 26px; }
  .article-aside {
    border-left: 0;
    border-top: 2px solid var(--ink);
    padding-left: 0;
    padding-top: 18px;
    position: static;
  }
  .cta-panel { grid-template-columns: 1fr; padding: 34px 24px; }
  .cta-panel .btn { justify-self: start; }
}

@media (max-width: 768px) {
  body { font-size: 16px; }
  .wrap { padding: 0 14px; }
  .head-bar { flex-wrap: wrap; padding: 10px 0; }
  .menu-btn { display: inline-flex; align-items: center; }
  .nav-main {
    display: none;
    width: 100%;
    margin-left: 0;
    border-top: 1px solid var(--rule);
  }
  .nav-main.open { display: block; }
  .nav-main ul {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 6px 0;
  }
  .nav-main a {
    display: flex;
    align-items: center;
    min-height: 46px;
    border-bottom: 1px solid var(--rule);
  }
  .stat-row { grid-template-columns: 1fr 1fr; }
  .feature-split { grid-template-columns: 1fr; gap: 20px; }
  .card-offset { grid-template-columns: 1fr; gap: 20px; }
  .card-offset article:nth-child(2) { margin-top: 0; }
  .check-list { grid-template-columns: 1fr; }
  .rows li { grid-template-columns: 1fr; gap: 6px; }
  .cat-list li { grid-template-columns: 1fr; gap: 12px; }
  .foot-grid { grid-template-columns: 1fr; gap: 20px; }
  .figure-right { float: none; width: 100%; margin: 1.4em 0; }
  section { padding: 36px 0; }
  .sec-head { flex-direction: column; gap: 4px; }
  .page-head { padding: 26px 0 18px; }
  .article-body h2 { margin-top: 1.5em; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; animation: none !important; }
}