:root{--ink:#122033;--muted:#53657a;--line:#dce6ef;--paper:#fff;--bg:#f6fafc;--orange:#ef6b2f;--orange-soft:#fff2e9;--green:#0d9b76;--green-soft:#e8f8f2;--blue:#2563eb;--shadow:0 18px 50px rgba(18,32,51,.08)}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB",Arial,sans-serif;line-height:1.75;-webkit-font-smoothing:antialiased}
a{color:var(--blue)}
.site-shell{max-width:1040px;margin:0 auto;padding:0 20px}
.site-header{padding:18px 0;border-bottom:1px solid var(--line);background:rgba(255,255,255,.9)}
.header-inner{display:flex;align-items:center;justify-content:space-between;gap:20px}
.brand{display:flex;align-items:center;gap:10px;color:var(--ink);text-decoration:none;font-weight:900;letter-spacing:-.02em}
.brand img{width:40px;height:40px;border-radius:12px;box-shadow:0 7px 18px rgba(18,32,51,.12)}
.brand small{display:block;color:var(--muted);font-size:11px;font-weight:700;letter-spacing:0}
.site-nav{display:flex;gap:6px;flex-wrap:wrap;justify-content:flex-end}
.site-nav a{padding:7px 10px;border-radius:10px;color:var(--muted);font-size:13px;font-weight:800;text-decoration:none}
.site-nav a:hover,.site-nav a:focus-visible{background:var(--orange-soft);color:var(--orange)}
.breadcrumb{display:flex;gap:8px;flex-wrap:wrap;margin:28px 0 18px;color:var(--muted);font-size:13px;font-weight:700}
.breadcrumb a{color:var(--muted);text-decoration:none}.breadcrumb a:hover{text-decoration:underline}
.article{max-width:850px;margin:0 auto;padding-bottom:56px}
.hero-card{padding:38px 34px 32px;background:linear-gradient(140deg,#fff 0%,#fffaf5 100%);border:1px solid var(--line);border-radius:26px;box-shadow:var(--shadow)}
.eyebrow{margin:0 0 8px;color:var(--green);font-size:13px;font-weight:900;letter-spacing:.06em}
h1{margin:0 0 14px;font-size:clamp(30px,5vw,48px);line-height:1.2;letter-spacing:-.04em}
.lede{margin:0;color:var(--muted);font-size:18px;line-height:1.7}
.answer{margin:26px 0;padding:20px 22px;background:var(--green-soft);border-left:4px solid var(--green);border-radius:12px;color:#174e42;font-size:17px}
.answer strong{color:#0b765b}
.content-grid{display:grid;grid-template-columns:minmax(0,1fr) 250px;gap:24px;align-items:start;margin-top:28px}
.content-main,.toc{background:var(--paper);border:1px solid var(--line);border-radius:22px;padding:28px;box-shadow:0 12px 32px rgba(18,32,51,.04)}
.content-main h2{margin:26px 0 10px;font-size:25px;line-height:1.35}.content-main h2:first-child{margin-top:0}
.content-main h3{margin:20px 0 7px;font-size:18px;line-height:1.4}
.content-main p{margin:10px 0;color:#33465b}.content-main ul,.content-main ol{padding-left:1.4em;color:#33465b}.content-main li{margin:6px 0}
.toc{position:sticky;top:18px}.toc h2{font-size:15px;margin:0 0 8px}.toc ul{padding-left:18px;margin:0}.toc li{margin:6px 0;font-size:13px}.toc a{text-decoration:none}
.callout{margin:22px 0;padding:17px 19px;border:1px solid #f5c8a9;background:var(--orange-soft);border-radius:14px;color:#744021}
.callout strong{color:#a2471c}.source-note{font-size:13px;color:var(--muted)}
.term-table{width:100%;border-collapse:collapse;margin:16px 0;font-size:15px}.term-table th,.term-table td{border:1px solid var(--line);padding:11px 12px;text-align:left;vertical-align:top}.term-table th{background:#f1f7fb;color:var(--ink)}
.faq-list details{padding:15px 0;border-bottom:1px solid var(--line)}.faq-list summary{cursor:pointer;font-weight:900;color:var(--ink)}.faq-list p{margin:8px 0 0;color:#40536a}
.article-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:11px;margin-top:24px}.article-links a{padding:13px 14px;border:1px solid var(--line);border-radius:12px;background:#fff;text-decoration:none;font-weight:800;color:var(--ink)}.article-links a:hover{border-color:#f3b48d;background:var(--orange-soft)}
.cta-row{display:flex;gap:12px;flex-wrap:wrap;margin-top:24px}.button{display:inline-block;padding:12px 17px;border-radius:12px;background:var(--orange);color:#fff;font-weight:900;text-decoration:none}.button.secondary{background:var(--ink)}
.site-footer{padding:28px 0 42px;border-top:1px solid var(--line);color:var(--muted);font-size:13px}.footer-links{display:flex;gap:16px;flex-wrap:wrap;margin-bottom:8px}.footer-links a{color:var(--muted);font-weight:800}
.updated{margin-top:24px;color:var(--muted);font-size:13px}
@media(max-width:760px){.header-inner{align-items:flex-start;flex-direction:column}.site-nav{justify-content:flex-start}.content-grid{grid-template-columns:1fr}.toc{position:static;order:-1}.hero-card{padding:28px 22px}.content-main{padding:22px}.article-links{grid-template-columns:1fr}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}