:root {
  --paper: #f6f6f9;
  --paper-deep: #e9e9f1;
  --white: #ffffff;
  --ink: #181817;
  --muted: #6d6962;
  --line: rgba(24, 24, 23, .16);
  --orange: #6754f7;
  --orange-dark: #513be5;
  --purple: #6754f7;
  --shell: 1210px;
  --ease: cubic-bezier(.2, .72, .2, 1);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: "Microsoft YaHei", "PingFang SC", system-ui, sans-serif; -webkit-font-smoothing: antialiased; }
body.menu-open { overflow: hidden; }
[id] { scroll-margin-top: 104px; }
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
button, input, textarea { font: inherit; }
button:focus-visible, a:focus-visible { outline: 2px solid var(--purple); outline-offset: 4px; }
.shell { width: min(calc(100% - 48px), var(--shell)); margin-inline: auto; }
.skip-link { position: fixed; left: 18px; top: -60px; z-index: 300; padding: 11px 16px; color: #fff; background: var(--ink); transition: top .2s; }
.skip-link:focus { top: 12px; }

/* Header */
.site-header { position: fixed; inset: 0 0 auto; z-index: 100; background: rgba(246, 246, 249, .94); border-bottom: 1px solid var(--line); backdrop-filter: blur(16px); }
.header-inner { height: 82px; display: flex; align-items: center; gap: 44px; }
.brand { width: 112px; flex: 0 0 auto; }
.brand img { width: 100%; height: auto; }
.desktop-nav { display: flex; align-items: center; gap: 34px; margin-left: auto; font-size: 13px; }
.desktop-nav a, .header-solutions { position: relative; }
.desktop-nav a::after, .header-solutions::after { content: ""; position: absolute; right: 0; bottom: -8px; left: 0; height: 1px; background: var(--orange); transform: scaleX(0); transform-origin: left; transition: transform .22s; }
.desktop-nav a:hover::after, .header-solutions:hover::after { transform: scaleX(1); }
.header-actions { display: flex; align-items: center; gap: 25px; margin-left: 20px; }
.header-solutions { font-size: 13px; }
.button { min-height: 50px; display: inline-flex; align-items: center; justify-content: center; gap: 18px; padding: 0 24px; border: 1px solid transparent; border-radius: 0; font-size: 14px; font-weight: 700; transition: color .2s, background .2s, transform .2s; }
.button:hover { transform: translateY(-2px); }
.button-small { min-height: 43px; padding-inline: 18px; color: #fff; background: var(--ink); }
.button-small:hover { background: var(--orange); }
.menu-toggle { width: 43px; height: 43px; display: none; position: relative; padding: 0; border: 1px solid var(--line); border-radius: 0; background: transparent; }
.menu-toggle span { position: absolute; left: 12px; width: 18px; height: 1.5px; background: var(--ink); transition: .25s; }
.menu-toggle span:first-child { top: 17px; }
.menu-toggle span:last-child { top: 24px; }
.menu-toggle[aria-expanded="true"] span:first-child { top: 21px; transform: rotate(45deg); }
.menu-toggle[aria-expanded="true"] span:last-child { top: 21px; transform: rotate(-45deg); }
.mobile-menu { position: absolute; top: 68px; right: 0; left: 0; height: calc(100dvh - 68px); overflow-y: auto; padding: 18px 20px 100px; color: var(--ink); background: var(--paper); border-top: 1px solid var(--line); }
.mobile-menu[hidden] { display: none; }
.mobile-menu a { min-height: 54px; display: flex; align-items: center; border-bottom: 1px solid var(--line); font-size: 18px; font-weight: 700; }
.mobile-menu .mobile-menu-cta { min-height: 52px; justify-content: center; margin-top: 18px; color: #fff; background: var(--orange); border: 0; }

/* Shared type */
.section { padding: 130px 0; }
.section-kicker, .eyebrow { margin: 0 0 22px; color: var(--orange); font-family: Arial, sans-serif; font-size: 10px; font-weight: 800; letter-spacing: .18em; }
.section-mark { display: flex; align-items: center; gap: 13px; color: var(--muted); font-size: 12px; white-space: nowrap; }
.section-mark span { width: 35px; height: 35px; display: grid; place-items: center; border: 1px solid var(--line); font-family: Arial, sans-serif; font-size: 9px; }
.section-mark b { font-weight: 500; letter-spacing: .08em; }
.text-link { display: inline-flex; align-items: center; gap: 14px; padding-bottom: 6px; border-bottom: 1px solid currentColor; font-size: 13px; font-weight: 700; }
.text-link span { color: var(--orange); }
.text-link.dark { color: var(--ink); }

/* Hero */
.about-hero { min-height: 930px; padding: 146px 0 0; overflow: hidden; background: var(--paper); }
.hero-layout { display: grid; grid-template-columns: .82fr 1.18fr; gap: 85px; align-items: center; }
.breadcrumb { display: flex; gap: 9px; margin-bottom: 58px; color: #8c877f; font-size: 11px; }
.breadcrumb b { color: var(--ink); font-weight: 500; }
.hero-copy h1 { margin: 0; font-size: clamp(54px, 6.1vw, 82px); font-weight: 690; line-height: 1.08; letter-spacing: -.06em; }
.hero-copy h1 em { color: var(--orange); font-style: normal; }
.hero-lead { max-width: 560px; margin: 34px 0 0; color: var(--muted); font-size: 17px; line-height: 1.95; }
.hero-actions { display: flex; align-items: center; gap: 32px; margin-top: 40px; }
.button-primary { color: #fff; background: var(--orange); }
.button-primary:hover { background: var(--orange-dark); }
.hero-visual { position: relative; margin: 0; border: 1px solid var(--line); background: var(--paper-deep); }
.hero-visual::before { content: "WORKING DOCUMENT / 01"; position: absolute; z-index: 2; top: 17px; right: 19px; color: rgba(24,24,23,.55); font: 8px Arial, sans-serif; letter-spacing: .13em; }
.hero-visual img { width: 100%; height: auto; }
.hero-visual figcaption { display: grid; grid-template-columns: 150px 1fr; gap: 22px; align-items: center; min-height: 86px; padding: 20px 24px; border-top: 1px solid var(--line); background: var(--white); }
.hero-visual figcaption span { color: var(--orange); font-size: 11px; }
.hero-visual figcaption b { font-size: 14px; line-height: 1.6; }
.hero-index { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 76px; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.hero-index a { min-height: 91px; display: flex; align-items: center; gap: 18px; padding: 18px 26px; border-left: 1px solid var(--line); transition: background .2s; }
.hero-index a:first-child { border-left: 0; }
.hero-index a:hover { background: var(--white); }
.hero-index small { color: var(--orange); font: 9px Arial, sans-serif; }
.hero-index span { font-size: 13px; font-weight: 700; }

/* Manifesto */
.manifesto { background: var(--white); }
.manifesto-layout { display: grid; grid-template-columns: 150px 1fr 250px; gap: 55px; align-items: start; }
.manifesto-main h2 { max-width: 780px; margin: 0; font-size: clamp(36px, 4.3vw, 57px); font-weight: 620; line-height: 1.34; letter-spacing: -.045em; }
.manifesto-body { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; margin-top: 65px; padding-top: 28px; border-top: 1px solid var(--line); }
.manifesto-body p { margin: 0; color: var(--muted); font-size: 15px; line-height: 1.95; }
.manifesto-note { margin-top: 52px; padding: 25px 23px; color: #fff; background: var(--orange); transform: rotate(2deg); }
.manifesto-note small { display: block; margin-bottom: 55px; font-size: 10px; opacity: .75; }
.manifesto-note p { margin: 0 0 48px; font-size: 21px; font-weight: 700; line-height: 1.55; }
.manifesto-note span { font: 8px Arial, sans-serif; letter-spacing: .1em; opacity: .65; }

/* Scope */
.scope { background: #eeeef4; }
.section-heading { display: grid; grid-template-columns: 150px 1fr 330px; gap: 55px; align-items: start; margin-bottom: 75px; }
.section-heading h2 { max-width: 700px; margin: 0; font-size: clamp(35px, 4.1vw, 54px); font-weight: 620; line-height: 1.32; letter-spacing: -.045em; }
.section-heading > p { margin: 40px 0 0; color: var(--muted); font-size: 14px; line-height: 1.9; }
.scope-table { border-top: 2px solid var(--ink); }
.scope-row { display: grid; grid-template-columns: 60px .72fr 1.2fr 110px; gap: 26px; align-items: center; min-height: 104px; border-bottom: 1px solid var(--line); transition: padding .22s, background .22s; }
.scope-row:hover { padding-inline: 18px; background: rgba(255,255,255,.42); }
.scope-row > span { color: var(--orange); font: 9px Arial, sans-serif; }
.scope-row > b { font-size: 24px; }
.scope-row p { margin: 0; color: var(--muted); font-size: 14px; }
.scope-row i { font-size: 11px; font-style: normal; text-align: right; }

/* Method */
.method { color: #fff; background: #1d1d1b; }
.method-layout { display: grid; grid-template-columns: .85fr 1.15fr; gap: 120px; }
.method .section-mark { color: rgba(255,255,255,.55); margin-bottom: 90px; }
.method .section-mark span { border-color: rgba(255,255,255,.23); }
.method-intro h2 { margin: 0; font-size: clamp(42px, 4.7vw, 61px); font-weight: 600; line-height: 1.25; letter-spacing: -.05em; }
.method-intro > p:last-child { max-width: 460px; margin: 36px 0 0; color: rgba(255,255,255,.55); line-height: 1.9; }
.method-list { margin: 0; padding: 0; border-top: 1px solid rgba(255,255,255,.22); list-style: none; }
.method-list li { display: grid; grid-template-columns: 74px 1fr; min-height: 155px; padding: 28px 0; border-bottom: 1px solid rgba(255,255,255,.22); }
.method-list > li > span { color: var(--orange); font: 10px Arial, sans-serif; }
.method-list small { color: rgba(255,255,255,.4); font: 8px Arial, sans-serif; letter-spacing: .16em; }
.method-list h3 { margin: 10px 0 8px; font-size: 25px; }
.method-list p { margin: 0; color: rgba(255,255,255,.52); font-size: 14px; line-height: 1.7; }

/* Principles */
.principles { background: var(--white); }
.section-heading.compact { grid-template-columns: 150px 1fr; margin-bottom: 78px; }
.section-heading.compact h2 { max-width: 800px; }
.principles-editorial { display: grid; grid-template-columns: 1.35fr 1fr 1fr; border-top: 2px solid var(--ink); border-bottom: 1px solid var(--line); }
.principles-editorial article { min-height: 260px; padding: 30px 28px; border-left: 1px solid var(--line); }
.principles-editorial article:first-child { grid-row: span 2; min-height: 521px; padding: 40px; border-left: 0; background: var(--paper); }
.principles-editorial article:nth-child(4) { grid-column: 2 / 4; min-height: 260px; border-top: 1px solid var(--line); }
.principles-editorial span { color: var(--orange); font: 9px Arial, sans-serif; }
.principles-editorial h3 { margin: 70px 0 18px; font-size: 25px; }
.principles-editorial .principle-lead h3 { max-width: 390px; margin-top: 180px; font-size: 46px; line-height: 1.2; letter-spacing: -.04em; }
.principles-editorial p { max-width: 440px; margin: 0; color: var(--muted); font-size: 14px; line-height: 1.85; }

/* Fit + FAQ */
.fit { background: var(--orange); }
.fit-layout { display: grid; grid-template-columns: .8fr 1.2fr; gap: 120px; color: #fff; }
.fit .section-kicker { color: #fff; opacity: .7; }
.fit-copy h2 { margin: 0; font-size: clamp(40px, 4.5vw, 58px); font-weight: 620; line-height: 1.28; letter-spacing: -.05em; }
.fit-copy > p { max-width: 450px; margin: 28px 0 34px; line-height: 1.9; opacity: .72; }
.fit .text-link { color: #fff; }
.fit .text-link span { color: #fff; }
.fit-lines { border-top: 1px solid rgba(255,255,255,.4); }
.fit-lines div { display: grid; grid-template-columns: 120px 1fr; gap: 34px; padding: 41px 0; border-bottom: 1px solid rgba(255,255,255,.4); }
.fit-lines b { font-size: 16px; }
.fit-lines p { margin: 0; font-size: 15px; line-height: 1.9; opacity: .78; }
.faq { background: var(--paper); }
.faq-layout { display: grid; grid-template-columns: .75fr 1.25fr; gap: 115px; }
.faq-intro { position: sticky; top: 125px; align-self: start; }
.faq-intro h2 { margin: 0; font-size: clamp(38px, 4.2vw, 54px); line-height: 1.28; letter-spacing: -.045em; }
.faq-intro > p { max-width: 430px; margin: 28px 0 32px; color: var(--muted); line-height: 1.9; }
.faq-list { border-top: 2px solid var(--ink); }
.faq-item { border-bottom: 1px solid var(--line); }
.faq-item button { width: 100%; display: grid; grid-template-columns: 42px 1fr 28px; gap: 16px; align-items: center; padding: 29px 0; border: 0; color: var(--ink); background: transparent; text-align: left; cursor: pointer; }
.faq-item button span { color: var(--orange); font: 9px Arial, sans-serif; }
.faq-item button b { font-size: 17px; }
.faq-item button i { width: 22px; height: 22px; position: relative; }
.faq-item button i::before, .faq-item button i::after { content: ""; position: absolute; left: 4px; top: 10px; width: 14px; height: 1.5px; background: var(--ink); transition: .2s; }
.faq-item button i::after { transform: rotate(90deg); }
.faq-item.open button i::after { transform: rotate(0); }
.faq-answer { display: grid; grid-template-rows: 0fr; transition: grid-template-rows .35s var(--ease); }
.faq-answer > p { min-height: 0; overflow: hidden; margin: 0; padding: 0 42px; color: var(--muted); line-height: 1.9; }
.faq-item.open .faq-answer { grid-template-rows: 1fr; }
.faq-item.open .faq-answer > p { padding-bottom: 30px; }

/* CTA + footer */
.final-cta { padding: 110px 0; color: #fff; background: var(--purple); }
.final-layout { display: grid; grid-template-columns: 1.35fr .65fr; gap: 90px; align-items: end; }
.final-layout small { color: rgba(255,255,255,.55); font: 9px Arial, sans-serif; letter-spacing: .16em; }
.final-layout h2 { margin: 18px 0 0; font-size: clamp(40px, 4.7vw, 62px); font-weight: 620; line-height: 1.25; letter-spacing: -.05em; }
.final-layout p { margin: 0 0 28px; color: rgba(255,255,255,.7); line-height: 1.8; }
.button-light { color: var(--ink); background: #fff; }
.site-footer { padding: 70px 0 0; background: #f0f0f4; }
.footer-main { display: grid; grid-template-columns: .9fr 1.1fr; gap: 90px; padding-bottom: 60px; }
.footer-brand img { width: 116px; }
.footer-brand p { max-width: 360px; margin: 26px 0 0; color: var(--muted); font-size: 13px; line-height: 1.85; }
.footer-links { display: grid; grid-template-columns: repeat(3, 1fr); gap: 35px; }
.footer-links div { display: flex; flex-direction: column; gap: 13px; font-size: 12px; }
.footer-links b { margin-bottom: 8px; font-size: 13px; }
.footer-links a { color: var(--muted); }
.footer-links a:hover { color: var(--orange); }
.footer-bottom { min-height: 72px; display: flex; align-items: center; justify-content: space-between; border-top: 1px solid var(--line); color: var(--muted); font-size: 11px; }
.footer-bottom span:last-child { display: flex; gap: 22px; }
.mobile-contact { display: none; }

/* Reveal */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.visible { opacity: 1; transform: none; }

@media (max-width: 1080px) {
  .desktop-nav { gap: 22px; }
  .header-solutions { display: none; }
  .hero-layout { grid-template-columns: .9fr 1.1fr; gap: 40px; }
  .manifesto-layout, .section-heading { grid-template-columns: 120px 1fr; }
  .manifesto-note, .section-heading > p { grid-column: 2; }
  .manifesto-note { width: 250px; margin: 10px 0 0 auto; }
  .section-heading > p { max-width: 590px; margin-top: -25px; }
  .method-layout, .fit-layout { gap: 70px; }
  .faq-layout { gap: 70px; }
}

@media (max-width: 820px) {
  .desktop-nav, .header-actions > .button-small { display: none; }
  .header-actions { margin-left: auto; }
  .menu-toggle { display: block; }
  .hero-layout { grid-template-columns: 1fr; }
  .hero-copy { max-width: 690px; }
  .hero-visual { max-width: 680px; }
  .manifesto-layout, .section-heading, .section-heading.compact { grid-template-columns: 1fr; }
  .manifesto-main, .manifesto-note, .section-heading > p { grid-column: auto; }
  .manifesto-note { margin-left: 0; }
  .section-heading > p { margin-top: 0; }
  .method-layout, .fit-layout, .faq-layout, .final-layout { grid-template-columns: 1fr; }
  .method .section-mark { margin-bottom: 45px; }
  .faq-intro { position: static; }
  .principles-editorial { grid-template-columns: 1fr 1fr; }
  .principles-editorial article:first-child { grid-column: 1 / 3; grid-row: auto; min-height: 360px; }
  .principles-editorial article:nth-child(4) { grid-column: 1 / 3; }
  .principles-editorial .principle-lead h3 { margin-top: 95px; }
}

@media (max-width: 560px) {
  body { padding-bottom: 62px; }
  [id] { scroll-margin-top: 80px; }
  .shell { width: min(calc(100% - 28px), var(--shell)); }
  .header-inner { height: 68px; }
  .brand { width: 92px; }
  .header-actions { gap: 0; }
  .section { padding: 82px 0; }
  .section-mark { margin-bottom: 40px; }
  .about-hero { min-height: auto; padding: 103px 0 0; }
  .breadcrumb { display: none; }
  .hero-copy h1 { font-size: clamp(42px, 13vw, 53px); line-height: 1.1; }
  .hero-lead { margin-top: 26px; font-size: 15px; line-height: 1.85; }
  .hero-actions { flex-direction: column; align-items: stretch; gap: 18px; margin-top: 30px; }
  .hero-actions .button { width: 100%; }
  .hero-actions .text-link { align-self: flex-start; }
  .hero-visual { margin-top: 26px; }
  .hero-visual figcaption { grid-template-columns: 1fr; gap: 6px; min-height: auto; padding: 16px; }
  .hero-index { grid-template-columns: 1fr 1fr; margin-top: 28px; }
  .hero-index a { min-height: 68px; padding: 12px 15px; }
  .hero-index a:nth-child(3) { border-left: 0; border-top: 1px solid var(--line); }
  .hero-index a:nth-child(4) { border-top: 1px solid var(--line); }
  .manifesto-main h2, .section-heading h2 { font-size: 32px; line-height: 1.4; }
  .manifesto-body { grid-template-columns: 1fr; gap: 24px; margin-top: 40px; }
  .manifesto-note { width: calc(100% - 25px); transform: rotate(1deg); }
  .manifesto-note small { margin-bottom: 35px; }
  .manifesto-note p { margin-bottom: 35px; }
  .section-heading { gap: 0; margin-bottom: 48px; }
  .section-heading > p { margin-top: 25px; }
  .scope-row { grid-template-columns: 34px 1fr 20px; gap: 10px; min-height: 98px; padding: 20px 0; }
  .scope-row:hover { padding-inline: 0; }
  .scope-row > b { font-size: 21px; }
  .scope-row p { grid-column: 2 / 4; font-size: 12px; line-height: 1.6; }
  .scope-row i { grid-column: 3; grid-row: 1; width: 20px; height: 20px; overflow: hidden; color: transparent; }
  .scope-row i::after { content: "↗"; color: var(--ink); }
  .method-layout { gap: 55px; }
  .method-intro h2, .fit-copy h2, .faq-intro h2 { font-size: 37px; }
  .method-list li { grid-template-columns: 48px 1fr; min-height: 145px; }
  .principles-editorial { grid-template-columns: 1fr; }
  .principles-editorial article, .principles-editorial article:first-child, .principles-editorial article:nth-child(4) { grid-column: auto; min-height: 230px; border-left: 0; border-top: 1px solid var(--line); }
  .principles-editorial article:first-child { min-height: 340px; }
  .principles-editorial .principle-lead h3 { margin-top: 90px; font-size: 37px; }
  .principles-editorial h3 { margin-top: 62px; }
  .fit-layout { gap: 56px; }
  .fit-lines div { grid-template-columns: 1fr; gap: 15px; }
  .faq-layout { gap: 55px; }
  .faq-item button { grid-template-columns: 30px 1fr 22px; gap: 8px; }
  .faq-item button b { font-size: 15px; }
  .faq-answer > p { padding-inline: 38px 10px; font-size: 13px; }
  .final-cta { padding: 78px 0; }
  .final-layout { gap: 40px; }
  .final-layout h2 { font-size: 36px; }
  .footer-main { grid-template-columns: 1fr; gap: 38px; padding-bottom: 42px; }
  .footer-links { grid-template-columns: 1fr 1fr; }
  .footer-links div:first-child { display: none; }
  .footer-bottom { min-height: 90px; flex-direction: column; align-items: flex-start; justify-content: center; gap: 10px; }
  .footer-bottom span:last-child { gap: 14px; }
  .mobile-contact { position: fixed; inset: auto 0 0; z-index: 90; display: grid; grid-template-columns: .8fr 1.2fr; height: 62px; padding: 7px; gap: 7px; border-top: 1px solid var(--line); background: rgba(246,246,249,.96); backdrop-filter: blur(12px); }
  .mobile-contact a { display: grid; place-items: center; border: 1px solid var(--line); background: var(--white); font-size: 13px; font-weight: 700; }
  .mobile-contact a:last-child { color: #fff; border-color: var(--orange); background: var(--orange); }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
  .reveal { opacity: 1; transform: none; }
}