:root {
  --bg: #f8fafc;
  --card: #ffffff;
  --text: #0f172a;
  --muted: #475569;
  --line: #e2e8f0;
  --accent: #0f766e;
  --shadow: 0 16px 40px rgba(15, 23, 42, 0.08);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: linear-gradient(180deg, #f8fafc 0%, #eef2ff 100%);
  color: var(--text);
  line-height: 1.7;
}
a { color: #0f766e; text-decoration: none; }
a:hover { text-decoration: underline; }
.container { width: min(1100px, calc(100% - 32px)); margin: 0 auto; }
.site-header {
  background: rgba(255,255,255,0.8);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(226,232,240,0.8);
  position: sticky;
  top: 0;
  z-index: 10;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 0;
}
.brand { font-weight: 800; font-size: 1.05rem; color: var(--text); }
.brand span { color: var(--accent); }
.nav a { margin-left: 18px; color: var(--muted); font-weight: 600; }
.hero { padding: 42px 0 24px; }
.hero-box, .card, .article-shell {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 24px;
  box-shadow: var(--shadow);
}
.hero-box { padding: 32px; }
.hero-kicker { text-transform: uppercase; letter-spacing: .12em; color: var(--accent); font-weight: 800; font-size: .8rem; }
.hero h1 { margin: 10px 0 10px; font-size: clamp(2rem, 4vw, 3.4rem); line-height: 1.12; }
.hero p { margin: 0; color: var(--muted); font-size: 1.04rem; max-width: 70ch; }
.section-title { margin: 34px 0 16px; font-size: 1.4rem; }
.featured-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  padding-bottom: 44px;
}
.card { padding: 20px; display: flex; flex-direction: column; gap: 12px; }
.card h2 { margin: 0; font-size: 1.2rem; line-height: 1.25; }
.card p { margin: 0; color: var(--muted); }
.card .meta { font-size: .88rem; color: #64748b; }
.pill { display: inline-flex; align-items: center; gap: 8px; width: fit-content; padding: 6px 12px; border-radius: 999px; background: #ecfeff; color: #0f766e; font-weight: 700; font-size: .86rem; }
.article-wrap { padding: 28px 0 52px; }
.article-shell { padding: 0; overflow: hidden; }
.article-body { padding: 0 28px 28px; }
.breadcrumbs { color: #64748b; font-size: .92rem; padding: 20px 28px 0; }
.article-hero { padding: 20px 28px 0; }
.article-hero h1 { margin: 14px 0 10px; font-size: clamp(2rem, 4vw, 3rem); line-height: 1.15; }
.meta-row { color: #64748b; font-size: .92rem; display: flex; flex-wrap: wrap; gap: 10px; }
.cover-svg { width: 100%; height: auto; display: block; }
.toc {
  border: 1px solid var(--line);
  background: #f8fafc;
  border-radius: 18px;
  padding: 18px 20px;
  margin: 24px 0 28px;
}
.toc h2 { margin: 0 0 10px; font-size: 1.05rem; }
.toc ol { margin: 0; padding-left: 20px; }
.toc li + li { margin-top: 8px; }
.article-content h2 { margin-top: 30px; margin-bottom: 10px; font-size: 1.55rem; }
.article-content p { margin: 0 0 16px; color: #1e293b; }
.article-content ul { margin: 0 0 16px 20px; }
.related {
  background: #eff6ff;
  border-radius: 18px;
  padding: 18px 20px;
  margin-top: 28px;
}
.related strong { display: block; margin-bottom: 10px; }
.conclusion {
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  color: #0f172a;
  font-weight: 500;
}
.footer {
  border-top: 1px solid var(--line);
  color: #64748b;
  padding: 24px 0 36px;
  font-size: .92rem;
}
@media (max-width: 800px) {
  .featured-grid { grid-template-columns: 1fr; }
  .nav { display: none; }
  .hero-box, .article-body, .article-hero, .breadcrumbs { padding-left: 18px; padding-right: 18px; }
}