:root {
  --primary: #5B4BDB;
  --primary-soft: #8B7CF6;
  --ink: #1E1B2E;
  --text: #292734;
  --muted: #6F6B7A;
  --bg: #F7F7FB;
  --surface: #FFFFFF;
  --surface-2: #EFEFFC;
  --accent: #F05A7E;
  --line: #DDDDF0;
  --shadow: 0 16px 44px rgba(30, 27, 46, .08);
  --radius: 22px;
  --radius-sm: 14px;
  --max: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}
img { display: block; max-width: 100%; height: auto; }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
button, input { font: inherit; }
.shell { width: min(calc(100% - 40px), var(--max)); margin-inline: auto; }
.skip-link { position: fixed; top: 8px; left: 8px; z-index: 999; transform: translateY(-160%); background: var(--ink); color: #fff; padding: 10px 14px; border-radius: 8px; }
.skip-link:focus { transform: none; }
.site-header { position: sticky; top: 0; z-index: 50; border-bottom: 1px solid rgba(221, 221, 240, .8); background: rgba(247, 247, 251, .94); backdrop-filter: blur(14px); }
.header-inner { min-height: 76px; display: flex; align-items: center; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 12px; color: var(--ink); min-width: 220px; }
.brand:hover { text-decoration: none; }
.brand-logo { width: 42px; height: 42px; object-fit: cover; border-radius: 12px; background: var(--surface-2); }
.brand-text { display: grid; line-height: 1.2; }
.brand-text strong { font-size: 1.25rem; letter-spacing: .03em; }
.brand-text small { margin-top: 4px; color: var(--muted); font-size: .78rem; }
.primary-nav { margin-left: auto; display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.primary-nav a { color: var(--text); padding: 9px 12px; border-radius: 999px; font-weight: 650; font-size: .94rem; }
.primary-nav a:hover, .primary-nav a.active { color: var(--primary); background: var(--surface-2); text-decoration: none; }
.menu-toggle { display: none; margin-left: auto; border: 1px solid var(--line); background: var(--surface); border-radius: 999px; padding: 8px 14px; color: var(--ink); }

.hero { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(320px, .95fr); gap: 70px; align-items: center; padding-block: 72px 58px; }
.eyebrow, .section-kicker { color: var(--primary); font-weight: 800; letter-spacing: .08em; text-transform: uppercase; font-size: .78rem; }
.hero h1, .page-hero h1 { color: var(--ink); font-size: clamp(2.3rem, 5vw, 4.9rem); line-height: 1.04; letter-spacing: -.04em; margin: 12px 0 22px; }
.hero-lead, .page-hero p { font-size: clamp(1.04rem, 1.6vw, 1.28rem); color: var(--muted); max-width: 760px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 26px; }
.btn { display: inline-flex; align-items: center; justify-content: center; min-height: 46px; padding: 0 19px; border-radius: 999px; font-weight: 800; border: 1px solid transparent; }
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn.primary { background: var(--primary); color: #fff; box-shadow: 0 12px 28px rgba(91,75,219,.18); }
.btn.secondary { border-color: var(--line); background: var(--surface); color: var(--ink); }
.quick-links { display: flex; flex-wrap: wrap; gap: 16px; margin-top: 22px; font-size: .93rem; }
.hero-visual { margin: 0; border-radius: 32px; overflow: hidden; background: var(--surface); box-shadow: var(--shadow); }
.hero-visual img { width: 100%; aspect-ratio: 4/3; object-fit: cover; }
.hero-visual figcaption { padding: 14px 18px 18px; color: var(--muted); font-size: .9rem; }

.intro-strip { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; padding-bottom: 62px; }
.intro-card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 26px; min-height: 250px; display: flex; flex-direction: column; }
.intro-card h2 { color: var(--ink); margin: 16px 0 8px; font-size: 1.35rem; }
.intro-card p { color: var(--muted); margin: 0 0 20px; }
.intro-card a { margin-top: auto; font-weight: 800; }
.pill { align-self: flex-start; background: var(--surface-2); color: var(--primary); padding: 6px 10px; border-radius: 999px; font-size: .78rem; font-weight: 800; }

.split-feature { display: grid; grid-template-columns: 1fr .95fr; gap: 48px; align-items: center; padding: 56px; border-radius: 34px; background: var(--ink); color: #fff; }
.split-feature h2 { font-size: clamp(1.8rem, 3vw, 3.1rem); line-height: 1.15; margin: 12px 0 20px; }
.split-feature p { color: #D5D2E3; }
.split-feature img { border-radius: 24px; width: 100%; aspect-ratio: 4/3; object-fit: cover; }
.split-feature .section-kicker { color: #BDB4FF; }
.split-feature .text-link { color: #fff; }
.check-list { list-style: none; padding: 0; display: grid; gap: 10px; margin: 26px 0; }
.check-list li { padding-left: 28px; position: relative; }
.check-list li::before { content: '✓'; position: absolute; left: 0; color: var(--accent); font-weight: 900; }
.text-link { font-weight: 850; }

.dense-section { padding-block: 78px; }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 30px; margin-bottom: 28px; }
.section-heading h2 { color: var(--ink); font-size: clamp(1.75rem, 3vw, 2.7rem); margin: 8px 0 0; }
.content-grid.compact { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.media-card { display: grid; grid-template-columns: 150px 1fr; gap: 20px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px; }
.media-card img { width: 150px; height: 150px; object-fit: cover; border-radius: 16px; }
.media-card h3 { margin: 6px 0 8px; font-size: 1.15rem; }
.media-card h3 a { color: var(--ink); }
.media-card p { color: var(--muted); margin: 0 0 10px; }
.tag-row { display: flex; flex-wrap: wrap; gap: 7px; }
.tag-row span { background: var(--surface-2); color: var(--primary); border-radius: 999px; padding: 4px 8px; font-size: .75rem; font-weight: 750; }

.utility-band { margin-bottom: 76px; display: grid; grid-template-columns: 1fr 260px; gap: 40px; align-items: center; padding: 34px 40px; background: var(--surface-2); border-radius: var(--radius); }
.utility-band h2 { color: var(--ink); margin: 6px 0 10px; }
.utility-band img { border-radius: 18px; width: 100%; aspect-ratio: 16/9; object-fit: cover; }
.faq-section { padding-bottom: 86px; }
.faq-list { display: grid; gap: 12px; }
details { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 0 20px; }
summary { cursor: pointer; padding: 18px 0; color: var(--ink); font-weight: 800; }
details p { margin-top: 0; color: var(--muted); }

.breadcrumbs { width: min(calc(100% - 40px), var(--max)); margin: 24px auto 0; }
.breadcrumbs ol { margin: 0; padding: 0; display: flex; flex-wrap: wrap; list-style: none; gap: 8px; color: var(--muted); font-size: .9rem; }
.breadcrumbs li:not(:last-child)::after { content: '/'; margin-left: 8px; color: #AAA6B8; }
.breadcrumbs a { color: var(--muted); }
.page-hero { padding-block: 56px 42px; }
.text-hero { max-width: 980px; }
.text-hero.narrow { max-width: 840px; }
.topic-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }
.image-hero, .app-hero, .video-hero { display: grid; grid-template-columns: 1fr .78fr; gap: 50px; align-items: center; }
.image-hero img, .app-hero img { border-radius: 28px; aspect-ratio: 16/11; object-fit: cover; box-shadow: var(--shadow); }

.editorial-list { display: grid; gap: 30px; padding-bottom: 72px; }
.editorial-row { display: grid; grid-template-columns: .8fr 1.2fr; gap: 46px; align-items: center; background: var(--surface); border: 1px solid var(--line); border-radius: 28px; padding: 28px; }
.editorial-row.reverse img { order: 2; }
.editorial-row img { border-radius: 20px; width: 100%; aspect-ratio: 4/3; object-fit: cover; }
.editorial-row h2 { color: var(--ink); font-size: clamp(1.5rem, 2.4vw, 2.3rem); margin: 8px 0 10px; }
.count { font-size: .78rem; font-weight: 900; color: var(--accent); letter-spacing: .08em; }
.lead-small { font-size: 1.04rem; color: var(--muted); }
.related-panel { margin-bottom: 82px; }
.related-panel h2 { color: var(--ink); font-size: 1.8rem; }
.related-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.related-grid a { display: grid; gap: 6px; padding: 22px; background: var(--surface-2); border-radius: 18px; color: var(--ink); }
.related-grid a:hover { text-decoration: none; outline: 2px solid rgba(91,75,219,.2); }
.related-grid span { color: var(--muted); font-size: .9rem; }

.topic-feed { display: grid; gap: 22px; padding-bottom: 64px; }
.topic-entry { display: grid; grid-template-columns: 64px 1fr 300px; gap: 28px; align-items: start; padding: 28px; border-bottom: 1px solid var(--line); }
.topic-index { font-size: 1.4rem; font-weight: 900; color: var(--primary-soft); }
.topic-entry h2 { font-size: clamp(1.45rem, 2.2vw, 2.05rem); margin: 10px 0; }
.topic-entry h2 a { color: var(--ink); }
.topic-entry img { width: 100%; aspect-ratio: 16/10; border-radius: 18px; object-fit: cover; }
.inline-note { margin-bottom: 80px; display: grid; grid-template-columns: 300px 1fr; gap: 34px; align-items: center; background: var(--surface); border: 1px solid var(--line); padding: 26px; border-radius: 26px; }
.inline-note img { border-radius: 18px; }

.stateless-search { background: var(--surface); border: 1px solid var(--line); border-radius: 20px; padding: 20px; box-shadow: var(--shadow); }
.stateless-search label { display: block; color: var(--ink); font-weight: 800; margin-bottom: 8px; }
.stateless-search input { width: 100%; border: 1px solid var(--line); border-radius: 12px; background: var(--bg); padding: 12px 14px; color: var(--text); }
.stateless-search p { font-size: .84rem; margin: 8px 0 0; color: var(--muted); }
.video-index { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; padding-bottom: 70px; }
.video-item { display: grid; grid-template-columns: 190px 1fr; gap: 18px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; }
.video-item[hidden] { display: none; }
.video-item img { width: 190px; height: 170px; border-radius: 16px; object-fit: cover; }
.video-item h2 { margin: 8px 0; font-size: 1.25rem; }
.video-item h2 a { color: var(--ink); }
.video-item p { margin: 0 0 12px; color: var(--muted); }
.callout-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; padding-bottom: 80px; }
.callout-grid article { background: var(--surface-2); border-radius: 24px; padding: 20px; }
.callout-grid img { width: 100%; aspect-ratio: 16/8; object-fit: cover; border-radius: 16px; }

.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-bottom: 58px; }
.steps article { background: var(--surface); border: 1px solid var(--line); border-radius: 22px; padding: 26px; }
.steps article > span { display: inline-grid; place-items: center; width: 36px; height: 36px; border-radius: 50%; background: var(--surface-2); color: var(--primary); font-weight: 900; }
.steps h2 { color: var(--ink); font-size: 1.3rem; }
.compact-split { margin-bottom: 78px; padding: 40px; }
.story-cards { display: grid; grid-template-columns: repeat(3,1fr); gap: 18px; margin-bottom: 66px; }
.story-cards article { background: var(--surface); border: 1px solid var(--line); border-radius: 24px; overflow: hidden; }
.story-cards img { width: 100%; aspect-ratio: 16/10; object-fit: cover; }
.story-cards div { padding: 20px; }
.story-cards h2 { margin: 0 0 8px; font-size: 1.3rem; color: var(--ink); }

.detail-article { display: grid; grid-template-columns: minmax(0,1fr) 260px; gap: 48px; padding-block: 56px 84px; }
.detail-main { max-width: 780px; }
.detail-main h1 { color: var(--ink); font-size: clamp(2rem, 4vw, 3.6rem); line-height: 1.1; margin: 14px 0 16px; }
.article-deck { color: var(--muted); font-size: 1.15rem; }
.detail-cover { width: 100%; aspect-ratio: 16/9; border-radius: 26px; object-fit: cover; margin: 28px 0 34px; }
.detail-main section { padding-block: 8px 14px; }
.detail-main h2 { color: var(--ink); }
.detail-aside { position: sticky; top: 100px; align-self: start; background: var(--surface); border: 1px solid var(--line); border-radius: 20px; padding: 20px; display: grid; gap: 10px; }
.detail-aside h2 { margin: 0 0 4px; font-size: 1.1rem; color: var(--ink); }
.detail-aside a { padding: 8px 0; border-bottom: 1px solid var(--line); }
.not-found { padding-block: 110px; min-height: 58vh; }
.not-found h1 { font-size: clamp(2.3rem, 5vw, 4.5rem); margin: 8px 0 14px; color: var(--ink); }
.not-found p { color: var(--muted); font-size: 1.1rem; max-width: 680px; }

.site-footer { background: var(--ink); color: #D8D5E4; padding: 50px 0 24px; }
.footer-grid { display: grid; grid-template-columns: 1.15fr .9fr 1fr; gap: 40px; }
.site-footer h2 { color: #fff; }
.site-footer nav { display: grid; gap: 8px; }
.site-footer a { color: #C9C2FF; }
.copyright { border-top: 1px solid rgba(255,255,255,.1); margin-top: 30px; padding-top: 18px; color: #9E9AAA; font-size: .86rem; }

:focus-visible { outline: 3px solid rgba(240,90,126,.5); outline-offset: 3px; }
@media (max-width: 980px) {
  .hero, .image-hero, .app-hero, .video-hero, .split-feature, .detail-article { grid-template-columns: 1fr; }
  .intro-strip, .story-cards, .steps, .related-grid { grid-template-columns: repeat(2, 1fr); }
  .content-grid.compact, .video-index { grid-template-columns: 1fr; }
  .topic-entry { grid-template-columns: 48px 1fr; }
  .topic-entry img { grid-column: 2; max-width: 420px; }
  .detail-aside { position: static; grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 760px) {
  .shell { width: min(calc(100% - 28px), var(--max)); }
  .header-inner { min-height: 68px; }
  .brand { min-width: 0; }
  .brand-text small { display: none; }
  .menu-toggle { display: inline-flex; }
  .primary-nav { display: none; position: absolute; left: 14px; right: 14px; top: 66px; padding: 12px; background: var(--surface); border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow); }
  .primary-nav.open { display: grid; }
  .primary-nav a { padding: 12px 14px; }
  .hero { gap: 30px; padding-block: 44px; }
  .hero h1, .page-hero h1 { font-size: clamp(2.15rem, 12vw, 3.4rem); }
  .intro-strip, .story-cards, .steps, .related-grid, .callout-grid, .footer-grid { grid-template-columns: 1fr; }
  .split-feature { padding: 28px; gap: 28px; }
  .section-heading { align-items: start; flex-direction: column; }
  .media-card, .video-item { grid-template-columns: 1fr; }
  .media-card img, .video-item img { width: 100%; height: auto; aspect-ratio: 16/9; }
  .utility-band, .inline-note { grid-template-columns: 1fr; }
  .topic-entry { grid-template-columns: 1fr; padding: 22px 0; }
  .topic-entry img { grid-column: 1; max-width: none; }
  .topic-index { font-size: .9rem; }
  .editorial-row { grid-template-columns: 1fr; gap: 22px; padding: 20px; }
  .editorial-row.reverse img { order: initial; }
  .detail-aside { grid-template-columns: 1fr; }
  .detail-article { gap: 28px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; animation: none !important; }
}

.support-hero { padding-bottom: 54px; }
.support-layout { display: grid; grid-template-columns: 240px minmax(0, 1fr); gap: 52px; align-items: start; padding-bottom: 86px; }
.support-toc { position: sticky; top: 100px; display: grid; gap: 6px; padding: 18px; border-radius: 18px; background: var(--surface); border: 1px solid var(--line); }
.support-toc strong { color: var(--ink); margin-bottom: 6px; }
.support-toc a { padding: 8px 10px; border-radius: 10px; color: var(--muted); font-size: .92rem; }
.support-toc a:hover { background: var(--surface-2); color: var(--primary); text-decoration: none; }
.support-copy { min-width: 0; }
.support-copy > section { scroll-margin-top: 100px; padding: 0 0 38px; margin-bottom: 38px; border-bottom: 1px solid var(--line); }
.support-copy h2, .prose-page h2 { color: var(--ink); font-size: clamp(1.55rem, 2.6vw, 2.25rem); line-height: 1.24; margin: 0 0 14px; }
.support-copy h3, .prose-page h3 { color: var(--ink); font-size: 1.15rem; margin-top: 26px; }
.support-copy p, .prose-page p { color: var(--text); margin: 0 0 16px; }
.support-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.support-actions a { display: inline-flex; align-items: center; min-height: 42px; padding: 0 14px; border-radius: 999px; background: var(--surface-2); color: var(--primary); font-weight: 800; }
.support-actions a:hover { background: #e5e3ff; text-decoration: none; }
.prose-page { max-width: 900px; padding-bottom: 90px; }
.prose-page > section { margin-bottom: 48px; }
.prose-page > section:not(.prose-callout) { padding-bottom: 36px; border-bottom: 1px solid var(--line); }
.prose-page p { font-size: 1.02rem; }
.prose-callout { padding: 28px; background: var(--surface-2); border-radius: 24px; }
.prose-callout h2 { margin-top: 0; }
@media (max-width: 820px) {
  .support-layout { grid-template-columns: 1fr; gap: 24px; }
  .support-toc { position: static; grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 520px) {
  .support-toc { grid-template-columns: 1fr; }
}