:root {
    --xh-primary: #f36f21;
    --xh-primary-light: #ff9f62;
    --xh-ink: #182033;
    --xh-muted: #667085;
    --xh-line: #e9edf4;
    --xh-surface: #f7f9fc;
    --xh-navy: #0c1324;
}

html { scroll-behavior: smooth; scroll-padding-top: 92px; }
body { display: block; min-height: 100vh; color: var(--xh-ink); background: #f7f9fc; font-family: -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif; line-height: 1.8; }
a { color: var(--xh-primary); transition: color .2s ease; }
a:hover { color: #d9580e; }
a:focus-visible { outline: 3px solid rgba(243,111,33,.3); outline-offset: 3px; }

.site-header { position: relative; overflow: hidden; padding: 0; color: #fff; background: var(--xh-navy); }
.site-header::before { content: ""; position: absolute; width: 360px; height: 360px; top: -220px; right: -100px; border-radius: 50%; background: rgba(243,111,33,.12); }
.article-nav { position: relative; z-index: 2; max-width: 1120px; height: 68px; margin: 0 auto; padding: 0 24px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid rgba(255,255,255,.08); }
.article-brand { display: inline-flex; align-items: center; gap: 10px; color: #fff; text-decoration: none; font-size: 16px; font-weight: 800; }
.article-brand:hover { color: #fff; }
.article-brand .logo { width: 36px; height: 36px; border-radius: 10px; }
.article-nav__links { display: flex; align-items: center; gap: 24px; }
.article-nav__links a { color: rgba(255,255,255,.72); text-decoration: none; font-size: 14px; font-weight: 600; }
.article-nav__links a:hover { color: #fff; }
.article-nav__links .article-nav__cta { padding: 8px 16px; color: #fff; border: 1px solid rgba(255,255,255,.3); border-radius: 999px; }

.article-hero { position: relative; z-index: 1; max-width: 820px; margin: 0 auto; padding: 52px 24px 68px; text-align: left; }
.article-hero__eyebrow { display: block; margin-bottom: 14px; color: #ffb98d; font-size: 13px; font-weight: 700; }
.article-hero h1 { margin: 0; color: #fff; font-size: clamp(34px,4.5vw,52px); line-height: 1.2; letter-spacing: -1.1px; }
.article-hero__summary { max-width: 720px; margin: 18px 0 0; color: rgba(255,255,255,.68); font-size: 15px; line-height: 1.85; }
.article-hero__meta { display: flex; flex-wrap: wrap; gap: 8px 18px; margin-top: 18px; color: rgba(255,255,255,.5); font-size: 12.5px; }
.article-hero__meta span + span::before { content: "·"; margin-right: 18px; }

body > .container { position: relative; z-index: 3; display: grid; grid-template-columns: 190px minmax(0,1fr); gap: 24px; width: min(1120px,calc(100% - 40px)); margin: 32px auto 72px; padding: 0; }
.sidebar { position: relative; width: auto; padding: 0; border: 0; background: transparent; }
.sidebar__inner { position: sticky; top: 24px; padding: 22px 18px; background: #fff; border: 1px solid var(--xh-line); border-radius: 16px; box-shadow: 0 12px 38px rgba(22,32,51,.07); }
.toc-title { display: flex; align-items: center; gap: 9px; margin: 0 0 14px; color: var(--xh-ink); font-size: 14px; font-weight: 800; }
.toc-title::before { content: ""; width: 4px; height: 17px; border-radius: 4px; background: linear-gradient(var(--xh-primary),var(--xh-primary-light)); }
.toc-list { margin: 0; padding: 0; list-style: none; }
.toc-item { margin: 0; }
.toc-link { display: block; padding: 9px 10px; color: var(--xh-muted); border-left: 2px solid transparent; text-decoration: none; font-size: 13px; line-height: 1.55; }
.toc-link:hover,.toc-link.active { color: var(--xh-primary); background: #fff8f4; border-left-color: var(--xh-primary); text-decoration: none; }

.main-content { display: grid; grid-template-columns: minmax(0,1fr) 190px; gap: 24px; align-items: start; min-width: 0; }
.content { min-width: 0; padding: 38px 44px 50px; background: #fff; border: 1px solid var(--xh-line); border-radius: 14px; }
.content article > h1,.content > article > .article-meta { display: none; }
.content h2 { position: relative; margin: 48px 0 20px; padding: 0 0 13px; color: var(--xh-ink); border-bottom: 1px solid var(--xh-line); font-size: 26px; line-height: 1.4; }
.content h2::after { content: ""; position: absolute; left: 0; bottom: -1px; width: 58px; height: 3px; border-radius: 3px; background: linear-gradient(90deg,var(--xh-primary),var(--xh-primary-light)); }
.content h3 { margin: 30px 0 13px; color: var(--xh-ink); font-size: 20px; }
.content p { margin: 0 0 18px; color: #475467; font-size: 16px; line-height: 1.95; }
.content strong { color: var(--xh-ink); }
.content img { display: block; width: auto !important; max-width: 100%; height: auto; margin: 24px auto 34px; padding: 7px; background: #fff; border: 1px solid var(--xh-line); border-radius: 14px; box-shadow: 0 12px 32px rgba(22,32,51,.09); }
.content li { margin: 0 0 12px 20px; padding-left: 5px; color: #475467; font-size: 16px; line-height: 1.8; }
.article-lead { margin: 0 0 24px !important; padding: 0 0 0 18px; color: #344054 !important; border-left: 3px solid var(--xh-primary); font-size: 16px; }

.table-wrap { overflow-x: auto; margin: 22px 0 32px; border: 1px solid var(--xh-line); border-radius: 14px; }
.center-table { width: 100%; min-width: 680px; border: 0; border-collapse: collapse; background: #fff; }
.center-table td { padding: 15px 12px; text-align: center; border: 0; border-bottom: 1px solid var(--xh-line); font-size: 14px; }
.center-table tr:first-child td { color: #fff; background: var(--xh-navy); font-weight: 800; }
.center-table tr:last-child td { border-bottom: 0; }
.center-table tr:nth-child(2) { background: #fff8f4; }
.center-table a { font-weight: 700; text-decoration: none; }
.selection-list { margin: 0 0 25px; padding: 20px 22px 10px 40px; background: var(--xh-surface); border: 1px solid var(--xh-line); border-radius: 12px; }

.recommendations { position: sticky; top: 24px; width: auto; padding: 18px; background: #fff; border: 1px solid var(--xh-line); border-radius: 12px; }
.recommendations h3 { margin: 0 0 8px; color: var(--xh-ink); font-size: 14px; }
.recommendation-link { position: relative; display: block; margin: 0; padding: 10px 0 10px 15px; color: #475467; text-decoration: none; font-size: 13px; line-height: 1.55; }
.recommendation-link::before { content: "→"; position: absolute; left: 0; color: var(--xh-primary); }
.recommendation-link:hover { color: var(--xh-primary); text-decoration: none; }
.recommendation-primary { display: block; margin-top: 10px; padding: 9px 12px; color: #fff; background: var(--xh-primary); border-radius: 8px; text-align: center; text-decoration: none; font-size: 13px; font-weight: 800; }
.recommendation-primary:hover { color: #fff; background: #dc5b11; text-decoration: none; }

footer { padding: 42px 24px; color: rgba(255,255,255,.55); background: var(--xh-navy); text-align: center; }
footer p { max-width: 920px; margin: 0 auto; font-size: 12px; line-height: 1.8; }
.friend-links { display: flex; flex-wrap: wrap; justify-content: center; gap: 20px; margin-top: 18px; }
.friend-link { color: rgba(255,255,255,.68); text-decoration: none; font-size: 13px; }
.friend-link:hover { color: #fff; text-decoration: none; }
.back-to-top { position: fixed; right: 24px; bottom: 24px; z-index: 20; display: flex; width: 44px; height: 44px; align-items: center; justify-content: center; color: #fff; background: var(--xh-primary); border-radius: 12px; box-shadow: 0 10px 28px rgba(243,111,33,.3); opacity: 0; visibility: hidden; text-decoration: none; transform: translateY(8px); transition: .2s ease; }
.back-to-top.visible { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover { color: #fff; background: #dc5b11; transform: translateY(-2px); }

@media (max-width: 1080px) {
    body > .container { grid-template-columns: 190px minmax(0,1fr); }
    .main-content { grid-template-columns: minmax(0,1fr); }
    .recommendations { position: static; display: grid; grid-template-columns: repeat(2,1fr); gap: 0 18px; }
    .recommendations h3,.recommendation-primary { grid-column: 1/-1; }
}
@media (max-width: 800px) {
    .article-nav { height: 64px; }
    .article-nav__links a:not(.article-nav__cta) { display: none; }
    .article-hero { padding: 42px 20px 52px; }
    body > .container { display: block; width: min(100% - 24px,760px); margin-top: 20px; }
    .sidebar { margin-bottom: 16px; }
    .sidebar__inner { position: static; padding: 15px; }
    .toc-list { display: flex; gap: 8px; overflow-x: auto; padding-bottom: 2px; }
    .toc-item { flex: 0 0 auto; }
    .toc-link { padding: 8px 11px; background: var(--xh-surface); border: 1px solid var(--xh-line); border-radius: 999px; white-space: nowrap; }
    .toc-link:hover,.toc-link.active { border-color: #ffd5bc; }
    .content { padding: 32px 24px 42px; border-radius: 16px; }
    .article-scenarios { grid-template-columns: 1fr; }
    .recommendations { grid-template-columns: 1fr; margin-top: 16px; }
}
@media (max-width: 520px) {
    .article-nav { padding: 0 16px; }
    .article-brand { font-size: 14px; }
    .article-brand .logo { width: 34px; height: 34px; }
    .article-nav__cta { display: none; }
    .article-hero h1 { font-size: 32px; }
    .article-hero__summary { font-size: 14px; }
    .content { padding: 28px 18px 36px; }
    .content h2 { font-size: 22px; }
    .content p,.content li { font-size: 15px; }
}
@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *,*::before,*::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}