:root {
  --ink: #07152f;
  --ink-2: #193054;
  --paper: #f5f7fb;
  --white: #ffffff;
  --line: #dbe2ed;
  --muted: #64748b;
  --orange: #ff9f43;
  --orange-2: #ff7a1a;
  --cyan: #53d7df;
  --radius: 20px;
  --shadow: 0 24px 70px rgba(7, 21, 47, .12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
button { font: inherit; }
.shell { width: min(1180px, calc(100% - 40px)); margin-inline: auto; }
.skip-link { position: fixed; left: 16px; top: -80px; z-index: 100; padding: 10px 14px; background: var(--white); border-radius: 8px; }
.skip-link:focus { top: 16px; }

.site-header { position: sticky; top: 0; z-index: 20; border-bottom: 1px solid rgba(219,226,237,.85); background: rgba(245,247,251,.88); backdrop-filter: blur(16px); }
.nav-wrap { min-height: 76px; display: flex; align-items: center; justify-content: space-between; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 12px; font-weight: 800; letter-spacing: -.02em; }
.brand-mark { width: 34px; height: 34px; position: relative; display: inline-flex; align-items: flex-end; gap: 3px; padding: 8px; border-radius: 10px; background: var(--ink); }
.brand-mark i { display: block; width: 4px; background: var(--orange); border-radius: 4px; }
.brand-mark i:nth-child(1) { height: 7px; }
.brand-mark i:nth-child(2) { height: 13px; }
.brand-mark i:nth-child(3) { height: 19px; background: var(--cyan); }
.site-nav { display: flex; align-items: center; gap: 26px; color: #42526a; font-size: .92rem; font-weight: 650; }
.site-nav a { position: relative; padding: 26px 0 22px; }
.site-nav a::after { content: ""; position: absolute; inset: auto 0 16px; height: 2px; transform: scaleX(0); background: var(--orange-2); transition: transform .2s ease; }
.site-nav a:hover::after, .site-nav a.active::after { transform: scaleX(1); }
.site-nav a.active { color: var(--ink); }
.nav-toggle { display: none; border: 1px solid var(--line); color: var(--ink); background: var(--white); border-radius: 10px; padding: 8px 12px; }

.hero { display: grid; grid-template-columns: 1.06fr .94fr; align-items: center; gap: 70px; min-height: 650px; padding-block: 76px 68px; }
.eyebrow { margin: 0 0 14px; color: #b8580b; font-size: .78rem; font-weight: 800; letter-spacing: .16em; text-transform: uppercase; }
.hero h1 { margin: 0; font-size: clamp(2.9rem, 5.5vw, 5.2rem); line-height: 1.06; letter-spacing: -.055em; }
.hero h1 span { color: transparent; background: linear-gradient(90deg, var(--orange-2), #e75028); background-clip: text; -webkit-background-clip: text; }
.hero-lead { max-width: 690px; margin: 28px 0 0; color: #53647b; font-size: 1.08rem; line-height: 1.95; }
.hero-actions { display: flex; gap: 12px; margin-top: 34px; }
.button { display: inline-flex; justify-content: center; align-items: center; min-height: 48px; padding: 0 20px; border: 1px solid var(--line); border-radius: 12px; font-weight: 760; transition: transform .2s ease, box-shadow .2s ease; }
.button:hover { transform: translateY(-2px); }
.button.primary { color: var(--white); border-color: var(--ink); background: var(--ink); box-shadow: 0 14px 30px rgba(7,21,47,.2); }
.button.ghost { background: rgba(255,255,255,.7); }
.principles { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin: 46px 0 0; }
.principles div { padding-top: 14px; border-top: 1px solid var(--line); }
.principles dt { color: var(--orange-2); font: 800 .74rem/1 Inter, sans-serif; }
.principles dd { margin: 8px 0 0; color: var(--ink-2); font-size: .88rem; font-weight: 700; }

.hero-board { position: relative; overflow: hidden; padding: 24px; color: var(--white); border: 1px solid rgba(255,255,255,.13); border-radius: 28px; background: radial-gradient(circle at 100% 0, #17386b 0, transparent 42%), var(--ink); box-shadow: var(--shadow); }
.hero-board::before { content: ""; position: absolute; inset: 0; opacity: .12; background-image: linear-gradient(rgba(255,255,255,.18) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.18) 1px, transparent 1px); background-size: 32px 32px; }
.board-head, .metric-grid, .board-line { position: relative; z-index: 1; }
.board-head { display: flex; justify-content: space-between; align-items: center; padding-bottom: 18px; border-bottom: 1px solid rgba(255,255,255,.14); font-size: .88rem; font-weight: 760; }
.signal { display: inline-flex; align-items: center; gap: 7px; color: #b9f5e3; font-size: .76rem; }
.signal::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: #46dfa9; box-shadow: 0 0 0 5px rgba(70,223,169,.12); }
.metric-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; margin-top: 20px; }
.metric-grid article { min-height: 132px; display: flex; flex-direction: column; justify-content: center; padding: 18px; border: 1px solid rgba(255,255,255,.1); border-radius: 16px; background: rgba(255,255,255,.055); }
.metric-grid article.accent { border-color: rgba(83,215,223,.35); background: linear-gradient(140deg, rgba(83,215,223,.2), rgba(255,159,67,.1)); }
.metric-grid span { color: #9fb1cb; font-size: .74rem; }
.metric-grid strong { margin-top: 5px; font-size: 1.04rem; }
.metric-grid small { margin-top: 13px; color: #a9b8cc; font-size: .7rem; }
.board-line { height: 80px; display: flex; align-items: flex-end; gap: 10px; margin-top: 22px; padding: 0 12px 4px; border-bottom: 1px solid rgba(255,255,255,.14); }
.board-line span { flex: 1; height: 20%; border-radius: 4px 4px 0 0; background: linear-gradient(var(--orange), var(--orange-2)); }
.board-line span:nth-child(2) { height: 42%; }.board-line span:nth-child(3) { height: 34%; }.board-line span:nth-child(4) { height: 68%; }.board-line span:nth-child(5) { height: 54%; }.board-line span:nth-child(6) { height: 86%; background: linear-gradient(var(--cyan), #269ea9); }

.section { padding-block: 76px; }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 30px; }
.section-heading h2 { margin: 0; font-size: clamp(2rem, 4vw, 3.2rem); line-height: 1.2; letter-spacing: -.04em; }
.text-link { font-weight: 750; color: var(--ink-2); }
.text-link span { color: var(--orange-2); }
.path-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.path-card { position: relative; min-height: 280px; display: grid; grid-template-columns: 52px 1fr 34px; gap: 20px; padding: 32px; overflow: hidden; border: 1px solid var(--line); border-radius: var(--radius); background: var(--white); transition: transform .25s ease, box-shadow .25s ease; }
.path-card:hover { transform: translateY(-5px); box-shadow: var(--shadow); }
.path-card::after { content: ""; position: absolute; right: -54px; bottom: -86px; width: 210px; height: 210px; border-radius: 50%; background: var(--orange); opacity: .1; }
.ai-path::after { background: var(--cyan); opacity: .16; }
.path-no { width: 42px; height: 42px; display: grid; place-items: center; color: var(--white); border-radius: 12px; background: var(--ink); font-weight: 800; font-size: .8rem; }
.path-card div > p:first-child { margin: 5px 0 12px; color: var(--muted); font-size: .72rem; font-weight: 800; letter-spacing: .13em; }
.path-card h3 { margin: 0; font-size: 1.75rem; }
.path-card div > p:last-child { max-width: 420px; margin: 20px 0 0; color: var(--muted); }
.path-arrow { align-self: start; font-size: 1.35rem; }

.article-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.article-card { display: flex; flex-direction: column; min-height: 320px; padding: 28px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--white); }
.article-card.featured-card { color: var(--white); background: var(--ink); border-color: var(--ink); }
.card-meta, .card-foot { display: flex; justify-content: space-between; gap: 14px; color: var(--muted); font-size: .76rem; }
.featured-card .card-meta, .featured-card .card-foot { color: #9fb1cb; }
.card-meta span { color: var(--orange-2); font-weight: 800; }
.article-card h3 { margin: 26px 0 14px; font-size: 1.38rem; line-height: 1.45; letter-spacing: -.02em; }
.article-card > p { margin: 0; color: var(--muted); }
.featured-card > p { color: #b8c5d8; }
.card-foot { margin-top: auto; padding-top: 30px; }
.card-foot a { color: inherit; font-weight: 750; }

.site-footer { margin-top: 60px; padding: 34px 0; color: #aebed3; background: var(--ink); }
.footer-row { display: flex; justify-content: space-between; gap: 36px; align-items: center; }
.footer-row strong { color: var(--white); }.footer-row p { margin: 4px 0 0; font-size: .82rem; }

.page-hero { padding: 82px 0 54px; border-bottom: 1px solid var(--line); }
.page-hero .kicker { color: var(--orange-2); font-size: .8rem; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; }
.page-hero h1 { max-width: 900px; margin: 12px 0 18px; font-size: clamp(2.6rem, 6vw, 5rem); line-height: 1.08; letter-spacing: -.055em; }
.page-hero > p { max-width: 720px; margin: 0; color: var(--muted); font-size: 1.08rem; }
.library-tools { display: flex; align-items: center; justify-content: space-between; gap: 18px; margin: 34px 0; }
.search-box { flex: 1; position: relative; max-width: 540px; }
.search-box input { width: 100%; min-height: 50px; padding: 0 18px 0 44px; color: var(--ink); border: 1px solid var(--line); border-radius: 13px; outline: none; background: var(--white); font: inherit; }
.search-box input:focus { border-color: #93a9c7; box-shadow: 0 0 0 4px rgba(25,48,84,.08); }
.search-box::before { content: "⌕"; position: absolute; left: 16px; top: 8px; color: var(--muted); font-size: 1.35rem; }
.filter-row { display: flex; flex-wrap: wrap; gap: 8px; }
.filter-row button { padding: 8px 13px; color: var(--ink-2); border: 1px solid var(--line); border-radius: 999px; background: var(--white); cursor: pointer; }
.filter-row button[aria-pressed="true"] { color: var(--white); border-color: var(--ink); background: var(--ink); }
.library-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.library-item { display: grid; grid-template-columns: 78px 1fr auto; gap: 22px; min-height: 190px; padding: 25px; border: 1px solid var(--line); border-radius: 18px; background: var(--white); }
.library-item[hidden] { display: none; }
.library-index { display: grid; place-items: center; align-self: start; aspect-ratio: 1; color: var(--white); border-radius: 16px; background: var(--ink); font-weight: 850; }
.library-copy .card-meta { justify-content: flex-start; margin-bottom: 13px; }
.library-copy h2 { margin: 0; font-size: 1.22rem; line-height: 1.45; }
.library-copy p { margin: 10px 0 0; color: var(--muted); font-size: .9rem; }
.library-go { align-self: center; color: var(--orange-2); font-size: 1.3rem; }
.empty-state { grid-column: 1 / -1; padding: 45px; text-align: center; color: var(--muted); border: 1px dashed var(--line); border-radius: 18px; }

.topic-intro { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: end; padding: 72px 0 45px; }
.topic-intro h1 { margin: 0; font-size: clamp(3rem, 7vw, 6.4rem); line-height: .98; letter-spacing: -.065em; }
.topic-intro h1 span { display: block; color: var(--orange-2); }
.topic-intro p { max-width: 560px; margin: 0; color: var(--muted); font-size: 1.08rem; }
.topic-tags { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 24px; }
.topic-tags span { padding: 7px 12px; border: 1px solid var(--line); border-radius: 999px; background: var(--white); font-size: .82rem; font-weight: 700; }
.topic-feature { display: grid; grid-template-columns: 1.1fr .9fr; overflow: hidden; margin: 28px 0 70px; color: var(--white); border-radius: 26px; background: var(--ink); }
.topic-feature > div { padding: 42px; }
.topic-feature .visual-panel { position: relative; min-height: 330px; display: grid; place-items: center; overflow: hidden; background: linear-gradient(140deg, #153b72, #0b1d3e); }
.topic-feature .visual-panel::before { content: ""; width: 210px; height: 210px; border: 1px solid rgba(255,255,255,.24); border-radius: 50%; box-shadow: 0 0 0 34px rgba(255,159,67,.09), 0 0 0 70px rgba(83,215,223,.06); }
.topic-feature .visual-panel::after { content: "ROI"; position: absolute; font-size: 3.6rem; font-weight: 900; letter-spacing: -.08em; }
.topic-feature .visual-panel.ai::after { content: "AI"; }
.topic-feature h2 { margin: 16px 0; font-size: 2.1rem; line-height: 1.25; }
.topic-feature p { color: #b8c5d8; }
.topic-feature .button { margin-top: 16px; color: var(--ink); background: var(--white); }

.guide-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.guide-card { padding: 28px; border: 1px solid var(--line); border-radius: 20px; background: var(--white); }
.guide-card .guide-no { color: var(--orange-2); font-weight: 850; }
.guide-card h2 { margin: 24px 0 12px; font-size: 1.35rem; }
.guide-card p { color: var(--muted); }
.guide-card ul { padding-left: 20px; color: var(--ink-2); }
.guide-card small { color: var(--muted); }

.about-layout { display: grid; grid-template-columns: .72fr 1.28fr; gap: 70px; padding: 76px 0; }
.profile-card { position: sticky; top: 110px; align-self: start; padding: 28px; color: var(--white); border-radius: 24px; background: var(--ink); }
.profile-symbol { width: 72px; height: 72px; display: grid; place-items: center; border-radius: 20px; color: var(--ink); background: var(--orange); font-size: 1.8rem; font-weight: 900; }
.profile-card h1 { margin: 22px 0 8px; font-size: 1.7rem; }
.profile-card p { color: #aebed3; }
.profile-card dl { margin: 28px 0 0; }
.profile-card dl div { display: flex; justify-content: space-between; gap: 14px; padding: 12px 0; border-top: 1px solid rgba(255,255,255,.12); }
.profile-card dt { color: #91a5c1; }.profile-card dd { margin: 0; font-weight: 700; }
.prose-lite h2 { margin: 0 0 18px; font-size: 2rem; letter-spacing: -.03em; }
.prose-lite h2:not(:first-child) { margin-top: 54px; }
.prose-lite p { color: #485a73; font-size: 1.04rem; }
.value-list { display: grid; gap: 12px; margin-top: 20px; }
.value-list div { display: grid; grid-template-columns: 42px 1fr; gap: 16px; padding: 20px; border: 1px solid var(--line); border-radius: 16px; background: var(--white); }
.value-list strong { color: var(--orange-2); }
.value-list p { margin: 0; }

.reading-progress { position: fixed; left: 0; right: 0; top: 0; z-index: 80; height: 3px; background: transparent; }
.reading-progress span { display: block; width: 0; height: 100%; background: var(--orange-2); }
.article-header { max-width: 900px; padding: 82px 0 46px; }
.article-header h1 { margin: 16px 0 22px; font-size: clamp(2.6rem, 6vw, 4.8rem); line-height: 1.12; letter-spacing: -.052em; }
.article-header .summary { max-width: 780px; color: var(--muted); font-size: 1.12rem; }
.article-meta { display: flex; flex-wrap: wrap; gap: 12px 24px; margin-top: 24px; color: var(--muted); font-size: .85rem; }
.article-layout { display: grid; grid-template-columns: minmax(0, 760px) 250px; justify-content: space-between; gap: 70px; padding-bottom: 90px; }
.article-body { min-width: 0; color: #31435d; font-size: 1.05rem; }
.article-body h2 { margin: 58px 0 18px; color: var(--ink); font-size: 2rem; line-height: 1.25; letter-spacing: -.03em; scroll-margin-top: 100px; }
.article-body h3 { margin: 34px 0 12px; color: var(--ink); font-size: 1.3rem; }
.article-body p, .article-body li { line-height: 1.9; }
.article-body ul, .article-body ol { padding-left: 24px; }
.article-body blockquote { margin: 30px 0; padding: 18px 22px; color: var(--ink-2); border-left: 4px solid var(--orange-2); border-radius: 0 14px 14px 0; background: #fff4e9; }
.article-body table { width: 100%; border-collapse: collapse; margin: 24px 0; background: var(--white); }
.article-body th, .article-body td { padding: 13px 14px; text-align: left; border: 1px solid var(--line); }
.article-body th { color: var(--ink); background: #edf1f7; }
.prompt-box { margin: 28px 0; overflow: hidden; border: 1px solid #2d466d; border-radius: 16px; background: var(--ink); }
.prompt-head { display: flex; justify-content: space-between; align-items: center; padding: 10px 14px; color: #9fb1cb; border-bottom: 1px solid rgba(255,255,255,.13); font-size: .78rem; }
.prompt-head button { padding: 5px 10px; color: var(--white); border: 1px solid rgba(255,255,255,.18); border-radius: 8px; background: rgba(255,255,255,.08); cursor: pointer; }
.prompt-box pre { margin: 0; padding: 20px; overflow-x: auto; color: #dce7f6; white-space: pre-wrap; font: .9rem/1.8 ui-monospace, SFMono-Regular, Consolas, monospace; }
.article-toc { position: sticky; top: 110px; align-self: start; padding: 20px; border-left: 1px solid var(--line); }
.article-toc strong { display: block; margin-bottom: 12px; }
.article-toc a { display: block; padding: 7px 0; color: var(--muted); font-size: .86rem; }
.article-toc a:hover { color: var(--orange-2); }

@media (max-width: 900px) {
  .library-tools { align-items: stretch; flex-direction: column; }
  .search-box { max-width: none; }
  .library-grid, .topic-intro, .topic-feature, .about-layout { grid-template-columns: 1fr; }
  .guide-grid { grid-template-columns: 1fr 1fr; }
  .topic-feature .visual-panel { min-height: 240px; }
  .profile-card { position: static; }
  .article-layout { grid-template-columns: 1fr; }
  .article-toc { position: static; grid-row: 1; border-left: 0; border-bottom: 1px solid var(--line); }
}

@media (max-width: 900px) {
  .nav-toggle { display: inline-flex; }
  .site-nav { position: absolute; left: 20px; right: 20px; top: 66px; display: none; flex-direction: column; align-items: stretch; gap: 0; padding: 10px; border: 1px solid var(--line); border-radius: 14px; background: var(--white); box-shadow: var(--shadow); }
  .site-nav.open { display: flex; }
  .site-nav a { padding: 11px 12px; border-radius: 8px; }
  .site-nav a::after { display: none; }
  .site-nav a:hover, .site-nav a.active { background: var(--paper); }
  .hero { grid-template-columns: 1fr; min-height: auto; gap: 50px; padding-top: 64px; }
  .path-grid, .article-grid { grid-template-columns: 1fr 1fr; }
  .article-card:last-child { grid-column: 1 / -1; }
}

@media (max-width: 640px) {
  .shell { width: min(100% - 28px, 1180px); }
  .nav-wrap { min-height: 66px; }
  .hero { padding-block: 48px 30px; }
  .hero h1 { font-size: clamp(2.55rem, 14vw, 4rem); }
  .hero-lead { font-size: 1rem; }
  .hero-actions { flex-direction: column; }
  .principles { gap: 10px; }
  .principles dd { font-size: .78rem; }
  .hero-board { padding: 18px; border-radius: 20px; }
  .metric-grid { grid-template-columns: 1fr; }
  .metric-grid article { min-height: 100px; }
  .section { padding-block: 54px; }
  .section-heading { align-items: start; flex-direction: column; }
  .path-grid, .article-grid { grid-template-columns: 1fr; }
  .path-card { grid-template-columns: 44px 1fr; padding: 24px; }
  .path-arrow { display: none; }
  .article-card:last-child { grid-column: auto; }
  .footer-row { align-items: start; flex-direction: column; }
  .page-hero { padding-top: 54px; }
  .library-grid, .guide-grid { grid-template-columns: 1fr; }
  .library-item { grid-template-columns: 58px 1fr; gap: 14px; padding: 20px; }
  .library-go { display: none; }
  .topic-feature > div { padding: 28px; }
  .article-header { padding-top: 52px; }
  .article-body { font-size: 1rem; }
  .article-body table { display: block; overflow-x: auto; white-space: nowrap; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}