:root { color-scheme: light; --ink:#0f172a; --muted:#475569; --line:#dbe4f0; --brand:#4f46e5; --soft:#eef2ff; --card:#fff; }
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: #f8fafc; font-family: Inter, -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif; line-height: 1.75; }
a { color: var(--brand); }
.site-header { position: sticky; top: 0; z-index: 10; display: flex; align-items: center; justify-content: space-between; gap: 18px; padding: 13px max(20px, calc((100vw - 1080px) / 2)); border-bottom: 1px solid rgba(219,228,240,.9); background: rgba(255,255,255,.94); backdrop-filter: blur(14px); }
.brand { color: var(--ink); font-size: 18px; font-weight: 800; text-decoration: none; }
.site-nav { display: flex; align-items: center; gap: 16px; font-size: 13px; }
.site-nav a { color: var(--muted); text-decoration: none; }
.site-nav .nav-cta { padding: 7px 13px; border-radius: 999px; background: var(--brand); color: #fff; font-weight: 700; }
.hero { padding: 72px 20px 54px; background: radial-gradient(circle at 80% 0, #e0e7ff 0, transparent 36%), linear-gradient(180deg,#fff,#f8fafc); }
.hero-inner, .article, .related { width: min(100%, 920px); margin: 0 auto; }
.eyebrow { display: inline-flex; padding: 5px 10px; border: 1px solid #c7d2fe; border-radius: 999px; background: #eef2ff; color: #4338ca; font-size: 12px; font-weight: 700; }
h1 { max-width: 820px; margin: 18px 0 14px; font-size: clamp(34px, 5vw, 58px); line-height: 1.14; letter-spacing: -.04em; }
.lead { max-width: 760px; margin: 0; color: var(--muted); font-size: clamp(16px, 2vw, 20px); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 28px; }
.button { display: inline-flex; align-items: center; justify-content: center; padding: 11px 17px; border: 1px solid #cbd5e1; border-radius: 9px; background: #fff; color: var(--ink); font-weight: 700; text-decoration: none; }
.button.primary { border-color: var(--brand); background: var(--brand); color: #fff; }
.article { padding: 48px 20px 64px; }
.article h2 { margin: 42px 0 12px; font-size: 27px; line-height: 1.3; }
.article h3 { margin: 24px 0 8px; font-size: 19px; }
.article p, .article li { color: #334155; }
.article ol, .article ul { padding-left: 22px; }
.fact-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin: 28px 0; }
.fact-card { padding: 18px; border: 1px solid var(--line); border-radius: 12px; background: var(--card); }
.fact-grid a.fact-card { color: inherit; text-decoration: none; transition: transform .16s ease, border-color .16s ease, box-shadow .16s ease; }
.fact-grid a.fact-card:hover { transform: translateY(-2px); border-color: #a7f3d0; box-shadow: 0 10px 24px rgba(15,23,42,.08); }
.fact-card strong { display: block; margin-bottom: 4px; }
.fact-card span { color: var(--muted); font-size: 13px; }
.sample-box, .warning-box { margin: 24px 0; padding: 20px; border-radius: 12px; }
.sample-box { border: 1px solid #c7d2fe; background: var(--soft); }
.warning-box { border: 1px solid #fed7aa; background: #fff7ed; }
.sample-box h2, .warning-box h2 { margin-top: 0; }
.faq details { padding: 14px 0; border-bottom: 1px solid var(--line); }
.faq summary { cursor: pointer; font-weight: 700; }
.final-cta { margin-top: 48px; padding: 28px; border-radius: 16px; background: #111827; color: #fff; }
.final-cta h2 { margin-top: 0; color: #fff; }
.final-cta p { color: #cbd5e1; }
.related { padding: 0 20px 54px; }
.related-links { display: flex; flex-wrap: wrap; gap: 10px; }
.related-links a { padding: 8px 12px; border: 1px solid var(--line); border-radius: 999px; background: #fff; text-decoration: none; }
.site-footer { padding: 28px 20px; border-top: 1px solid var(--line); color: #64748b; text-align: center; font-size: 12px; }
@media (max-width: 720px) { .site-header { position: static; } .site-nav a:not(.nav-cta) { display: none; } .hero { padding-top: 46px; } .fact-grid { grid-template-columns: 1fr; } }