:root {
  --ink: #13211f;
  --muted: #61706d;
  --line: #dfe8e4;
  --paper: #f6f8f5;
  --card: #ffffff;
  --teal: #0d6b62;
  --teal-dark: #084c46;
  --amber: #e2a14e;
  --shadow: 0 18px 55px rgba(27, 65, 60, 0.09);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--paper);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); line-height: 1.75; }
a { color: inherit; text-decoration: none; }
a:hover { color: var(--teal); }
.shell { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }
.topbar { padding: 25px 0; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 11px; font-weight: 800; letter-spacing: .02em; }
.brand-mark { width: 30px; height: 30px; display: grid; place-items: center; color: white; background: var(--teal); border-radius: 9px; font-size: 13px; }
.nav { display: flex; gap: 20px; color: var(--muted); font-size: 14px; }
.nav a { padding: 4px 0; }
.hero { padding: 68px 0 76px; display: grid; grid-template-columns: 1.1fr .9fr; gap: 64px; align-items: end; }
.eyebrow { color: var(--teal); font-size: 12px; font-weight: 800; letter-spacing: .18em; text-transform: uppercase; }
h1, h2, h3 { margin: 0; line-height: 1.18; letter-spacing: -.035em; }
h1 { margin-top: 18px; max-width: 690px; font-size: clamp(42px, 6vw, 76px); }
.lead { max-width: 640px; margin: 24px 0 0; color: var(--muted); font-size: 18px; }
.hero-note { padding: 26px; background: #e7f0eb; border: 1px solid #d4e4dc; border-radius: 22px; box-shadow: var(--shadow); }
.hero-note strong { display: block; margin-bottom: 10px; color: var(--teal-dark); }
.hero-note p { margin: 0; color: #3f5b55; font-size: 14px; }
.section-head { padding: 0 0 22px; display: flex; justify-content: space-between; align-items: baseline; gap: 18px; border-bottom: 1px solid var(--line); }
.section-head h2 { font-size: 26px; }
.section-head span { color: var(--muted); font-size: 13px; }
.grid { padding: 28px 0 90px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.card { padding: 25px; min-height: 295px; display: flex; flex-direction: column; background: var(--card); border: 1px solid var(--line); border-radius: 18px; box-shadow: 0 8px 28px rgba(27, 65, 60, 0.045); transition: transform .2s ease, box-shadow .2s ease; }
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.tag { color: var(--teal); font-size: 12px; font-weight: 800; letter-spacing: .08em; }
.card h3 { margin-top: 22px; font-size: 24px; }
.card p { margin: 14px 0 24px; color: var(--muted); font-size: 14px; }
.card-foot { margin-top: auto; display: flex; justify-content: space-between; gap: 12px; color: var(--muted); font-size: 12px; }
.arrow { color: var(--teal); font-weight: 800; }
.footer { padding: 24px 0 40px; color: var(--muted); border-top: 1px solid var(--line); font-size: 13px; }
.article-wrap { padding: 55px 0 88px; max-width: 790px; }
.article-meta { margin-top: 18px; color: var(--muted); font-size: 13px; }
.article { margin-top: 48px; font-size: 17px; }
.article h2 { margin: 44px 0 14px; font-size: 30px; }
.article h3 { margin: 28px 0 10px; font-size: 21px; }
.article p { margin: 0 0 20px; }
.article ul { margin: 0 0 22px; padding-left: 24px; }
.article li { margin: 8px 0; }
.article blockquote { margin: 28px 0; padding: 18px 22px; color: #3f5b55; background: #e7f0eb; border-left: 4px solid var(--teal); border-radius: 0 12px 12px 0; }
.article code { padding: 2px 6px; background: #edf2ef; border-radius: 5px; font-size: .9em; }
.article pre { overflow: auto; padding: 18px; color: #e7f0eb; background: #13211f; border-radius: 12px; font-size: 14px; }
.article a { color: var(--teal); text-decoration: underline; text-underline-offset: 3px; }
.back { display: inline-block; margin-bottom: 28px; color: var(--teal); font-size: 14px; font-weight: 700; }
@media (max-width: 780px) {
  .shell { width: min(100% - 28px, 650px); }
  .topbar { padding: 18px 0; }
  .nav { gap: 12px; font-size: 12px; }
  .hero { padding: 46px 0 54px; grid-template-columns: 1fr; gap: 28px; }
  h1 { font-size: clamp(42px, 13vw, 64px); }
  .lead { font-size: 16px; }
  .grid { grid-template-columns: 1fr; padding-bottom: 55px; }
  .article-wrap { padding-top: 35px; }
  .article { font-size: 16px; }
}