:root {
  --bg: #fbfaf7;
  --surface: #ffffff;
  --ink: #16201c;
  --muted: #5b6862;
  --line: #e4e2db;
  --brand: #0f6b4f;
  --brand-ink: #ffffff;
  --accent: #e5483b;
  --hl-bg: #fff1c2;
  --banner-bg: #16201c;
  --banner-ink: #f3f1ea;
  --radius: 14px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101513;
    --surface: #171e1b;
    --ink: #e9ede9;
    --muted: #9aa8a1;
    --line: #2a3430;
    --brand: #3fbf8f;
    --brand-ink: #08130e;
    --accent: #ff6f61;
    --hl-bg: #3a3214;
    --banner-bg: #3fbf8f;
    --banner-ink: #08130e;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.65 var(--font); }
a { color: var(--brand); text-underline-offset: 3px; }
.wrap { max-width: 1040px; margin: 0 auto; padding: 0 20px; }
.muted { color: var(--muted); }
.small { font-size: 14px; }

/* banner */
.banner { background: var(--banner-bg); color: var(--banner-ink); text-align: center; font-size: 14px; padding: 9px 16px; }
.banner.live { background: var(--accent); color: #fff; }

/* header */
.site-header { border-bottom: 1px solid var(--line); background: var(--bg); position: sticky; top: 0; z-index: 5; }
.bar { display: flex; align-items: center; justify-content: space-between; height: 62px; gap: 12px; }
.logo { display: inline-flex; align-items: center; gap: 8px; color: var(--ink); text-decoration: none; font-weight: 700; font-size: 20px; letter-spacing: -.01em; }
.logo b { color: var(--brand); }
.logo-mark { width: 26px; height: 26px; color: var(--accent); }
.logo.sm { font-size: 17px; }
.logo.sm .logo-mark { width: 22px; height: 22px; }
.site-header nav { display: flex; gap: 18px; align-items: center; font-size: 15px; }
.site-header nav a { color: var(--ink); text-decoration: none; }
.site-header nav a:hover { color: var(--brand); }
.site-header nav .lang { border: 1px solid var(--line); border-radius: 999px; padding: 3px 12px; font-size: 14px; }

/* hero */
.hero { padding: 64px 0 40px; max-width: 880px; }
.eyebrow { text-transform: uppercase; letter-spacing: .08em; font-size: 12.5px; font-weight: 600; color: var(--muted); margin: 0 0 12px; }
h1 { font-size: clamp(32px, 5.2vw, 52px); line-height: 1.12; letter-spacing: -.02em; margin: 0 0 18px; }
.hl { background: linear-gradient(transparent 58%, var(--hl-bg) 58%); }
.lede { font-size: 18.5px; color: var(--muted); margin: 0 0 28px; max-width: 640px; }
.cta { display: flex; flex-wrap: wrap; gap: 12px; }
.btn { display: inline-block; padding: 12px 20px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: var(--ink); text-decoration: none; font-weight: 600; font-size: 15.5px; }
.btn:hover { border-color: var(--brand); }
.btn.primary { background: var(--brand); color: var(--brand-ink); border-color: var(--brand); }
.btn.primary:hover { filter: brightness(1.08); }
.btn.sm { padding: 8px 16px; font-size: 14.5px; }

/* sections */
.block { padding: 36px 0; border-top: 1px solid var(--line); }
.block h2 { font-size: 24px; letter-spacing: -.01em; margin: 0 0 18px; }
.features { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.features article { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 22px; }
.features h3 { margin: 0 0 6px; font-size: 17.5px; }
.features p { margin: 0; color: var(--muted); font-size: 15.5px; }
.tag { display: inline-block; font-size: 11.5px; font-weight: 600; text-transform: uppercase; letter-spacing: .05em; color: var(--accent); border: 1px solid currentColor; border-radius: 6px; padding: 0 6px; vertical-align: 2px; margin-left: 4px; }
.cats { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; margin-top: 16px; }
.cat { display: flex; gap: 12px; align-items: flex-start; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px 16px; }
.cat-i { font-size: 22px; line-height: 1.2; }
.cat strong { display: block; font-size: 15.5px; }
.cat small { display: block; color: var(--muted); font-size: 13px; line-height: 1.45; }
.note p { max-width: 720px; color: var(--muted); }

/* prose */
.prose { max-width: 720px; padding: 52px 0 40px; }
.prose h1 { font-size: clamp(30px, 4.4vw, 42px); }
.prose h2 { font-size: 21px; margin: 34px 0 8px; }
.prose p, .prose li { font-size: 17px; }
.prose ul { padding-left: 22px; }
.prose li { margin: 6px 0; }
.prose.center { text-align: center; margin: 0 auto; }
.callout { margin: 36px 0 20px; padding: 20px 22px; border-radius: var(--radius); background: var(--surface); border: 1px solid var(--line); border-left: 4px solid var(--brand); display: flex; flex-wrap: wrap; gap: 12px 16px; align-items: center; justify-content: space-between; }

/* footer */
.site-footer { border-top: 1px solid var(--line); margin-top: 40px; padding: 28px 0 22px; }
.foot { display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.foot p { margin: 6px 0 0; font-size: 14px; }
.foot-links { display: flex; flex-wrap: wrap; gap: 8px 20px; align-content: flex-start; font-size: 14.5px; }
.foot-links a { color: var(--ink); text-decoration: none; }
.foot-links a:hover { color: var(--brand); }
.copy { margin-top: 18px; }

@media (max-width: 860px) {
  .cats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 600px) {
  .wrap { padding: 0 16px; }
  .features, .cats { grid-template-columns: 1fr; }
  .hero { padding: 40px 0 28px; }
  .lede { font-size: 17px; }
  .site-header nav { gap: 12px; font-size: 14px; }
}