:root {
  --ink: #101828;
  --muted: #667085;
  --line: #e4e7ec;
  --brand: #1664ff;
  --brand-soft: #eef4ff;
  --surface: #ffffff;
  --page: #f7f9fc;
  --max: 1120px;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--page);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.75;
}
a { color: inherit; }
.site-header {
  min-height: 68px;
  padding: 0 5vw;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  background: rgba(255,255,255,.96);
  border-bottom: 1px solid var(--line);
}
.brand { color: var(--ink); font-weight: 800; text-decoration: none; }
.site-header nav { display: flex; gap: 24px; }
.site-header nav a { color: var(--muted); text-decoration: none; }
.site-header nav a[aria-current="page"] { color: var(--brand); font-weight: 700; }
main { width: min(var(--max), 90vw); margin: 0 auto; }
.hero { padding: 76px 0 42px; max-width: 760px; }
.hero h1 { margin: 8px 0 12px; font-size: clamp(34px, 5vw, 58px); line-height: 1.12; }
.hero p:last-child { color: var(--muted); font-size: 18px; }
.eyebrow { margin: 0; color: var(--brand); font-size: 12px; font-weight: 800; letter-spacing: .14em; }
.cluster-nav { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 32px; }
.cluster-nav a {
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  text-decoration: none;
}
.cluster-nav a.active { color: #fff; background: var(--brand); border-color: var(--brand); }
.article-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; padding-bottom: 72px; }
.article-card, .empty-state {
  padding: 28px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 18px;
}
.article-card h2 { margin: 6px 0 10px; font-size: 23px; line-height: 1.35; }
.article-card h2 a, .read-more { text-decoration: none; }
.article-card > p:not(.article-cluster) { color: var(--muted); }
.article-cluster { margin: 0; color: var(--brand); font-size: 13px; font-weight: 750; }
.read-more { color: var(--brand); font-weight: 700; }
.article-shell { max-width: 820px; padding-bottom: 80px; }
.breadcrumb { display: flex; gap: 8px; padding: 28px 0; color: var(--muted); font-size: 14px; }
.breadcrumb a { text-decoration: none; }
.article-shell article {
  padding: clamp(24px, 5vw, 60px);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 22px;
}
.article-header h1 { margin: 10px 0 16px; font-size: clamp(32px, 5vw, 50px); line-height: 1.2; }
.article-summary { color: var(--muted); font-size: 18px; }
.article-header time { color: var(--muted); font-size: 14px; }
.article-body { margin-top: 42px; }
.article-body h1 { font-size: 32px; line-height: 1.3; }
.article-body h2 { margin-top: 40px; font-size: 26px; line-height: 1.35; }
.article-body h3 { margin-top: 30px; font-size: 20px; }
.article-body a { color: var(--brand); }
.article-body li { margin-bottom: 6px; }
.faq { margin-top: 48px; padding-top: 32px; border-top: 1px solid var(--line); }
.faq-item { padding: 18px 0; border-bottom: 1px solid var(--line); }
.faq-item h3 { margin: 0 0 6px; }
.faq-item p { margin: 0; color: var(--muted); }
.article-cta { margin-top: 48px; padding: 28px; border-radius: 16px; background: var(--brand-soft); }
.article-cta h2 { margin: 8px 0; }
.article-cta a { display: inline-block; margin-top: 8px; color: var(--brand); font-weight: 750; text-decoration: none; }
footer { padding: 28px 5vw; color: var(--muted); text-align: center; border-top: 1px solid var(--line); }

@media (max-width: 720px) {
  .site-header { align-items: flex-start; padding-top: 18px; padding-bottom: 18px; }
  .site-header nav { gap: 12px; font-size: 14px; }
  .article-grid { grid-template-columns: 1fr; }
  .article-shell article { border-radius: 16px; }
}

html {
  color-scheme: light;
  scroll-behavior: smooth;
}

body {
  min-width: 0;
  -webkit-font-smoothing: antialiased;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(14px);
}

.site-header nav a,
.cluster-nav a,
.article-card,
.read-more {
  transition: color .18s ease, border-color .18s ease,
              background-color .18s ease, transform .18s ease,
              box-shadow .18s ease;
}

.site-header nav a:hover,
.breadcrumb a:hover {
  color: var(--brand);
}

.article-card:hover {
  transform: translateY(-2px);
  border-color: #cbd8f6;
  box-shadow: 0 16px 40px rgba(16, 24, 40, .08);
}

.article-body {
  overflow-wrap: anywhere;
}

.article-body p,
.article-body ul,
.article-body ol,
.article-body blockquote {
  margin: 16px 0;
}

.article-body blockquote {
  padding: 12px 18px;
  color: var(--muted);
  background: var(--brand-soft);
  border-left: 4px solid var(--brand);
  border-radius: 0 10px 10px 0;
}

.back-to-insights {
  display: inline-flex;
  margin-top: 28px;
  color: var(--brand);
  font-weight: 700;
  text-decoration: none;
}

@media (max-width: 720px) {
  main {
    width: min(100% - 32px, var(--max));
  }

  .site-header {
    position: static;
    flex-direction: column;
    gap: 10px;
  }

  .hero {
    padding: 48px 0 28px;
  }

  .article-shell {
    width: min(100% - 24px, 820px);
  }

  .article-shell article {
    padding: 24px 20px;
  }

  .breadcrumb {
    overflow-wrap: anywhere;
  }
}