:root {
  --ink: #0b1324;
  --ink-2: #121e34;
  --panel: #17243d;
  --line: #2c3a55;
  --paper: #f6f2ea;
  --muted: #aab6c9;
  --mint: #55d6c2;
  --coral: #ff647c;
  --sun: #f6c85f;
  --sky: #9ed7e8;
  --max: 1180px;
  --radius: 6px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--paper);
  background: var(--ink);
  font-family: "Microsoft YaHei", "Noto Sans SC", Arial, sans-serif;
  line-height: 1.75;
  font-size: 16px;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
.wrap { width: min(var(--max), calc(100% - 40px)); margin: 0 auto; }
.skip-link { position: absolute; left: -9999px; }
.skip-link:focus { left: 16px; top: 12px; padding: 8px 12px; background: var(--sun); color: var(--ink); z-index: 20; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(11, 19, 36, .96);
  border-bottom: 1px solid var(--line);
}
.nav-shell { min-height: 76px; display: flex; align-items: center; justify-content: space-between; gap: 22px; }
.brand { display: inline-flex; align-items: center; gap: 11px; font-weight: 700; letter-spacing: .04em; }
.brand img { width: 43px; height: 43px; object-fit: cover; border-radius: 10px; }
.brand-name { color: var(--paper); font-size: 19px; white-space: nowrap; }
.nav-links { display: flex; align-items: center; gap: 6px; }
.nav-links a { color: var(--muted); padding: 8px 13px; border: 1px solid transparent; border-radius: var(--radius); font-size: 14px; }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--paper); border-color: var(--line); background: var(--ink-2); }
.nav-cta { background: var(--coral) !important; border-color: var(--coral) !important; color: var(--ink) !important; font-weight: 700; }
.menu-toggle { display: none; border: 1px solid var(--line); background: transparent; color: var(--paper); border-radius: var(--radius); width: 42px; height: 38px; font-size: 22px; }

.hero { padding: 86px 0 76px; border-bottom: 1px solid var(--line); }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(300px, .8fr); gap: 64px; align-items: center; }
.eyebrow { margin: 0 0 15px; color: var(--mint); font-size: 13px; letter-spacing: .16em; text-transform: uppercase; }
h1, h2, h3 { margin: 0; line-height: 1.22; letter-spacing: .01em; }
h1 { color: var(--paper); font-size: clamp(36px, 6vw, 68px); max-width: 650px; }
.hero-copy { margin: 24px 0 0; color: var(--muted); max-width: 630px; font-size: 18px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 31px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 46px; padding: 0 20px; border: 1px solid var(--mint); color: var(--ink); background: var(--mint); border-radius: var(--radius); font-weight: 700; transition: transform .18s ease, background .18s ease; }
.button:hover { transform: translateY(-2px); background: #8be9da; }
.button.alt { background: transparent; color: var(--paper); border-color: var(--line); }
.button.alt:hover { border-color: var(--mint); color: var(--mint); }
.hero-note { margin: 16px 0 0; color: #7f8ca3; font-size: 13px; }
.hero-art { position: relative; border: 1px solid var(--line); background: var(--ink-2); padding: 24px; min-height: 330px; overflow: hidden; }
.hero-art::before, .hero-art::after { content: ""; position: absolute; height: 1px; background: var(--mint); opacity: .55; transform: rotate(-18deg); }
.hero-art::before { width: 350px; top: 72px; left: 80px; }
.hero-art::after { width: 250px; top: 124px; left: 140px; background: var(--coral); }
.hero-art-inner { position: relative; z-index: 1; display: flex; min-height: 280px; align-items: flex-end; justify-content: space-between; gap: 20px; }
.hero-art-title { align-self: flex-start; max-width: 210px; }
.hero-art-title strong { display: block; color: var(--sun); font-size: 48px; line-height: 1; }
.hero-art-title span { display: block; margin-top: 12px; color: var(--paper); font-size: 14px; }
.hero-art-screen { width: 165px; padding: 8px; background: #1e2b45; border: 1px solid #455674; transform: rotate(5deg); box-shadow: 13px 13px 0 rgba(85,214,194,.16); }
.hero-art-screen img { width: 100%; height: 230px; object-fit: cover; object-position: top; }

.stat-bar { border-bottom: 1px solid var(--line); background: var(--ink-2); }
.stats { display: grid; grid-template-columns: repeat(4, 1fr); }
.stat { padding: 25px 20px; border-right: 1px solid var(--line); }
.stat:last-child { border-right: 0; }
.stat strong { display: block; color: var(--sun); font-size: 29px; line-height: 1.1; }
.stat span { display: block; margin-top: 6px; color: var(--muted); font-size: 13px; }

.section { padding: 86px 0; border-bottom: 1px solid var(--line); }
.section-head { display: flex; align-items: end; justify-content: space-between; gap: 20px; margin-bottom: 35px; }
.section-kicker { margin: 0 0 10px; color: var(--coral); font-size: 13px; letter-spacing: .16em; }
h2 { font-size: clamp(28px, 4vw, 42px); }
.section-lead { max-width: 480px; margin: 0; color: var(--muted); }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 15px; }
.feature { min-height: 215px; padding: 24px; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); }
.feature-number { color: var(--mint); font-size: 13px; font-weight: 700; }
.feature h3 { margin-top: 18px; font-size: 21px; }
.feature p { margin: 11px 0 0; color: var(--muted); font-size: 14px; }
.feature strong { color: var(--paper); }

.preview-layout { display: grid; grid-template-columns: .78fr 1.22fr; gap: 38px; align-items: start; }
.preview-intro { position: sticky; top: 105px; }
.preview-intro p { color: var(--muted); }
.preview-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 15px; }
.preview-card { margin: 0; padding: 11px; border: 1px solid var(--line); background: var(--panel); border-radius: var(--radius); }
.preview-card img { width: 100%; max-width: 400px; height: 260px; object-fit: cover; object-position: top; margin: 0 auto; }
.preview-card figcaption { padding: 12px 5px 2px; color: var(--muted); font-size: 13px; }

.split { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.text-panel { padding: 30px; background: var(--ink-2); border: 1px solid var(--line); border-radius: var(--radius); }
.text-panel h3 { font-size: 23px; }
.text-panel p { margin: 15px 0 0; color: var(--muted); }
.link-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.text-link { color: var(--mint); border-bottom: 1px solid var(--mint); font-size: 14px; }
.text-link:hover { color: var(--sun); border-color: var(--sun); }

.quote-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 15px; }
.quote { margin: 0; padding: 25px; min-height: 190px; border-left: 3px solid var(--coral); background: var(--panel); }
.quote p { margin: 0; color: var(--paper); font-size: 17px; }
.quote cite { display: block; margin-top: 20px; color: var(--muted); font-size: 13px; font-style: normal; }

.faq-list { border-top: 1px solid var(--line); }
.faq-item { border-bottom: 1px solid var(--line); }
.faq-question { width: 100%; padding: 20px 0; border: 0; background: transparent; color: var(--paper); text-align: left; font: inherit; display: flex; justify-content: space-between; gap: 15px; cursor: pointer; }
.faq-question span:last-child { color: var(--mint); font-size: 22px; line-height: 1; }
.faq-answer { display: none; padding: 0 35px 21px 0; color: var(--muted); font-size: 14px; }
.faq-item.is-open .faq-answer { display: block; }
.faq-item.is-open .faq-question span:last-child { transform: rotate(45deg); }

.page-hero { padding: 75px 0 60px; border-bottom: 1px solid var(--line); background: var(--ink-2); }
.page-hero h1 { font-size: clamp(35px, 5vw, 58px); }
.page-hero p { max-width: 750px; margin: 21px 0 0; color: var(--muted); font-size: 17px; }
.article { padding: 72px 0; }
.article-grid { display: grid; grid-template-columns: minmax(0, 1fr) 290px; gap: 55px; align-items: start; }
.article-main { min-width: 0; }
.article-main h2 { margin: 42px 0 16px; font-size: 30px; }
.article-main h2:first-child { margin-top: 0; }
.article-main h3 { margin: 30px 0 8px; font-size: 21px; color: var(--mint); }
.article-main p { margin: 0 0 18px; color: #d6deeb; }
.article-main ul, .article-main ol { margin: 0 0 22px; padding-left: 23px; color: #d6deeb; }
.article-main li { margin: 8px 0; }
.article-main a { color: var(--mint); border-bottom: 1px solid rgba(85,214,194,.5); }
.toc { position: sticky; top: 105px; padding: 21px; border: 1px solid var(--line); background: var(--panel); border-radius: var(--radius); }
.toc strong { color: var(--sun); font-size: 13px; letter-spacing: .12em; }
.toc a { display: block; margin-top: 10px; color: var(--muted); font-size: 14px; }
.toc a:hover { color: var(--mint); }
.notice { padding: 17px 20px; border-left: 3px solid var(--sun); background: rgba(246,200,95,.08); color: var(--paper); }
.step-list { counter-reset: guide; display: grid; gap: 13px; margin: 25px 0; }
.step { counter-increment: guide; display: grid; grid-template-columns: 45px 1fr; gap: 15px; padding: 20px; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); }
.step::before { content: counter(guide, decimal-leading-zero); color: var(--coral); font-weight: 700; font-size: 22px; }
.step h3 { margin: 0; color: var(--paper); font-size: 19px; }
.step p { margin: 7px 0 0; }
.answer-block { padding: 22px 24px; margin-bottom: 13px; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); }
.answer-block h3 { margin: 0; color: var(--paper); font-size: 18px; }
.answer-block p { margin: 9px 0 0; }

.download-band { padding: 58px 0; background: var(--coral); color: var(--ink); }
.download-band .download-inner { display: flex; align-items: center; justify-content: space-between; gap: 22px; }
.download-band h2 { max-width: 600px; }
.download-band .download-note { margin: 9px 0 0; color: #3e1620; }
.download-band .button { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.download-band .button:hover { background: var(--ink-2); }
.site-footer { padding: 38px 0 26px; background: #080f1d; color: var(--muted); }
.footer-grid { display: grid; grid-template-columns: 1.2fr 1fr 1fr; gap: 30px; }
.footer-title { margin: 0 0 13px; color: var(--paper); font-size: 16px; }
.footer-brand { color: var(--paper); font-size: 19px; font-weight: 700; }
.footer-text { margin: 8px 0 0; font-size: 13px; }
.footer-links a { display: block; margin: 6px 0; font-size: 13px; }
.footer-links a:hover { color: var(--mint); }
.disclaimer { margin: 26px 0 0; padding-top: 18px; border-top: 1px solid var(--line); font-size: 12px; color: #7f8ca3; }
.copyright { margin: 9px 0 0; color: #61708a; font-size: 12px; }

@media (max-width: 860px) {
  .nav-links { display: none; position: absolute; left: 20px; right: 20px; top: 70px; flex-direction: column; align-items: stretch; padding: 10px; background: var(--ink-2); border: 1px solid var(--line); }
  .nav-links.is-open { display: flex; }
  .nav-links a { padding: 11px 13px; }
  .menu-toggle { display: block; }
  .hero-grid, .preview-layout, .article-grid { grid-template-columns: 1fr; gap: 35px; }
  .preview-intro, .toc { position: static; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .quote-grid { grid-template-columns: 1fr; }
  .download-band .download-inner { align-items: flex-start; flex-direction: column; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 560px) {
  .wrap { width: min(var(--max), calc(100% - 28px)); }
  .hero { padding: 60px 0; }
  h1 { font-size: 40px; }
  .hero-art { min-height: 280px; padding: 18px; }
  .hero-art-screen { width: 137px; }
  .hero-art-screen img { height: 195px; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .stat:nth-child(2) { border-right: 0; }
  .stat:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .feature-grid, .preview-list, .split { grid-template-columns: 1fr; }
  .section { padding: 62px 0; }
  .section-head { display: block; }
  .section-lead { margin-top: 15px; }
  .footer-grid { grid-template-columns: 1fr; }
  .article { padding: 52px 0; }
  .article-main h2 { font-size: 27px; }
}