:root {
  --paper: #f5f5ef;
  --white: #ffffff;
  --ink: #121714;
  --muted: #59625d;
  --line: #cfd5d0;
  --mint: #28d79e;
  --mint-soft: #dff8ed;
  --coral: #ff6f59;
  --yellow: #f3dc66;
  --container: 1180px;
  --header-height: 76px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", Arial, Helvetica, sans-serif; line-height: 1.75; letter-spacing: 0; }
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }
button, a { -webkit-tap-highlight-color: transparent; }
[id] { scroll-margin-top: 92px; }

.site-header { position: sticky; top: 0; z-index: 50; width: 100%; background: rgba(245, 245, 239, .96); border-bottom: 1px solid var(--ink); }
.header-inner { width: min(var(--container), calc(100% - 48px)); height: var(--header-height); margin: 0 auto; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 11px; font-weight: 900; font-size: 19px; white-space: nowrap; }
.brand img { width: 44px; height: 44px; border: 1px solid var(--ink); }
.site-nav { display: flex; align-items: center; gap: 28px; font-size: 14px; font-weight: 700; }
.site-nav a { position: relative; padding: 8px 0; }
.site-nav a:not(.nav-download)::after { content: ""; position: absolute; left: 0; right: 100%; bottom: 2px; height: 2px; background: var(--ink); transition: right .2s ease; }
.site-nav a:hover::after, .site-nav a.active::after { right: 0; }
.site-nav .nav-download { padding: 9px 18px; background: var(--ink); color: var(--white); border: 1px solid var(--ink); }
.site-nav .nav-download:hover { background: var(--mint); color: var(--ink); }
.menu-toggle { display: none; width: 42px; height: 42px; border: 1px solid var(--ink); background: transparent; align-items: center; justify-content: center; flex-direction: column; gap: 5px; cursor: pointer; }
.menu-toggle span { width: 18px; height: 2px; background: var(--ink); transition: transform .2s, opacity .2s; }

.section-inner, .hero-inner, .footer-inner { width: min(var(--container), calc(100% - 48px)); margin: 0 auto; }
.hero { border-bottom: 1px solid var(--ink); overflow: hidden; }
.hero-inner { min-height: 700px; display: grid; grid-template-columns: minmax(0, 1fr) minmax(520px, .92fr); gap: 58px; align-items: center; padding: 54px 0 48px; }
.hero-copy { align-self: center; }
.eyebrow { display: flex; align-items: center; justify-content: space-between; width: 100%; max-width: 530px; margin-bottom: 26px; padding-bottom: 10px; border-bottom: 1px solid var(--ink); font-size: 12px; font-weight: 900; }
.eyebrow b { display: grid; place-items: center; width: 30px; height: 30px; background: var(--coral); }
h1, h2, h3, p { margin-top: 0; }
.hero h1 { max-width: 610px; margin-bottom: 24px; font-size: 64px; line-height: 1.03; font-weight: 950; letter-spacing: 0; }
.hero-copy > p { max-width: 600px; margin-bottom: 28px; color: #343d38; font-size: 17px; line-height: 1.9; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 30px; }
.button { min-height: 48px; padding: 11px 22px; display: inline-flex; align-items: center; justify-content: center; border: 1px solid var(--ink); font-size: 15px; font-weight: 850; line-height: 1.2; transition: transform .2s, background .2s, color .2s; }
.button:hover { transform: translateY(-2px); }
.button-primary { background: var(--mint); }
.button-ghost { background: transparent; }
.button-dark { color: var(--white); background: var(--ink); }
.hero-facts { display: grid; grid-template-columns: repeat(3, 1fr); max-width: 600px; margin: 0; border-top: 1px solid var(--line); }
.hero-facts div { padding: 16px 14px 0 0; }
.hero-facts dt { color: var(--muted); font-size: 11px; font-weight: 800; text-transform: uppercase; }
.hero-facts dd { margin: 3px 0 0; font-size: 14px; font-weight: 800; }

.hero-media { position: relative; width: 100%; height: 565px; align-self: center; border-left: 1px solid var(--ink); border-right: 1px solid var(--ink); background: linear-gradient(90deg, transparent 49.8%, rgba(18,23,20,.16) 50%, transparent 50.2%); }
.media-label { position: absolute; top: 0; left: 16px; writing-mode: vertical-rl; font-size: 10px; font-weight: 900; }
.phone-shot { position: absolute; margin: 0; background: var(--white); border: 1px solid var(--ink); box-shadow: 9px 9px 0 var(--ink); overflow: hidden; }
.phone-shot img { width: 100%; height: auto; max-width: 400px; }
.phone-shot figcaption { display: flex; align-items: center; justify-content: space-between; padding: 6px 8px; border-top: 1px solid var(--ink); font-size: 10px; font-weight: 800; background: var(--paper); }
.phone-shot figcaption b { color: var(--coral); }
.shot-main { z-index: 3; width: 250px; left: 54px; top: 60px; }
.shot-side { width: 142px; right: 28px; box-shadow: 6px 6px 0 var(--ink); }
.shot-side-top { top: 15px; transform: rotate(2deg); }
.shot-side-bottom { bottom: 22px; transform: rotate(-2deg); }

.signal-strip { border-bottom: 1px solid var(--ink); background: var(--ink); color: var(--white); }
.signal-grid { min-height: 58px; display: grid; grid-template-columns: repeat(6, 1fr); align-items: center; text-align: center; font-size: 12px; font-weight: 800; }
.signal-grid span { border-right: 1px solid #46504a; }
.signal-grid span:last-child { border: 0; }
.section { padding: 96px 0; border-bottom: 1px solid var(--ink); }
.section-heading { margin-bottom: 44px; display: flex; justify-content: space-between; align-items: end; gap: 48px; }
.section-heading h2 { margin: 4px 0 0; font-size: 44px; line-height: 1.1; font-weight: 950; }
.section-heading > p { max-width: 560px; margin-bottom: 0; color: var(--muted); font-size: 15px; }
.section-no { display: block; color: var(--coral); font-size: 11px; font-weight: 900; }
.gallery-section { background: var(--white); }
.gallery-grid { display: grid; grid-template-columns: 1.45fr 1fr 1fr; gap: 20px; align-items: end; }
.gallery-item { margin: 0; }
.gallery-frame { height: 480px; padding: 22px; display: grid; place-items: center; background: var(--paper); border: 1px solid var(--ink); overflow: hidden; }
.gallery-item img { width: auto; max-width: 400px; max-height: 100%; height: auto; object-fit: contain; filter: drop-shadow(7px 8px 0 rgba(18,23,20,.18)); }
.gallery-featured .gallery-frame { height: 555px; background: var(--mint-soft); }
.gallery-item figcaption { display: flex; flex-direction: column; gap: 3px; padding-top: 13px; }
.gallery-item figcaption b { font-size: 16px; }
.gallery-item figcaption span { color: var(--muted); font-size: 13px; }

.features-section { background: var(--yellow); }
.feature-layout { display: grid; grid-template-columns: .78fr 1.22fr; gap: 80px; align-items: start; }
.vertical-heading { display: block; position: sticky; top: 112px; margin: 0; }
.vertical-heading h2 { margin-bottom: 18px; }
.vertical-heading .section-copy p { margin-bottom: 22px; }
.text-link, .route-grid a { display: inline-flex; gap: 8px; font-size: 14px; font-weight: 900; border-bottom: 1px solid var(--ink); }
.feature-list { border-top: 1px solid var(--ink); }
.feature-list article { display: grid; grid-template-columns: 58px 1fr; gap: 22px; padding: 25px 0; border-bottom: 1px solid var(--ink); }
.feature-list article > span { font-size: 13px; font-weight: 900; }
.feature-list h3 { margin-bottom: 6px; font-size: 21px; }
.feature-list p { margin: 0; color: #39413d; }

.route-section { background: var(--paper); }
.route-grid { display: grid; grid-template-columns: repeat(3, 1fr); border: 1px solid var(--ink); }
.route-grid article { min-height: 290px; padding: 28px; border-right: 1px solid var(--ink); display: flex; flex-direction: column; align-items: flex-start; }
.route-grid article:last-child { border: 0; }
.route-index { display: grid; place-items: center; width: 34px; height: 34px; margin-bottom: 42px; background: var(--coral); border: 1px solid var(--ink); font-weight: 900; }
.route-grid h3 { font-size: 22px; margin-bottom: 10px; }
.route-grid p { flex: 1; color: var(--muted); }
.faq-preview { background: var(--white); }
.faq-preview-layout { display: grid; grid-template-columns: .75fr 1.25fr; gap: 80px; }
.faq-list { border-top: 1px solid var(--ink); }
.faq-list details { border-bottom: 1px solid var(--ink); }
.faq-list summary { position: relative; padding: 20px 48px 20px 0; list-style: none; cursor: pointer; font-weight: 850; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; position: absolute; right: 10px; top: 17px; font-size: 22px; font-weight: 400; }
.faq-list details[open] summary::after { content: "−"; }
.faq-list details p { padding: 0 48px 20px 0; margin: 0; color: var(--muted); }
.faq-more { display: flex; justify-content: space-between; padding: 20px 0; font-weight: 900; }
.download-band { padding: 70px 0; color: var(--white); background: var(--coral); border-bottom: 1px solid var(--ink); }
.download-inner { display: flex; align-items: center; justify-content: space-between; gap: 36px; }
.download-inner .section-no { color: var(--ink); }
.download-inner h2 { margin: 5px 0 7px; font-size: 42px; line-height: 1.1; }
.download-inner p { margin: 0; }

.site-footer { padding: 44px 0 28px; color: var(--white); background: var(--ink); }
.footer-inner { display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 26px 40px; }
.footer-brand { display: flex; align-items: center; gap: 10px; }
.footer-brand img { border: 1px solid var(--white); }
.footer-inner nav { display: flex; gap: 25px; font-size: 13px; }
.disclaimer { grid-column: 1 / -1; margin: 0; padding-top: 24px; border-top: 1px solid #4c534f; color: #c7ceca; text-align: center; font-size: 12px; }
.copyright { grid-column: 1 / -1; margin: 0; color: #8e9993; text-align: center; font-size: 12px; }

.inner-hero { padding: 80px 0; background: var(--mint-soft); border-bottom: 1px solid var(--ink); }
.inner-hero-grid { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(320px, .6fr); gap: 80px; align-items: center; }
.inner-hero h1 { max-width: 760px; margin: 10px 0 22px; font-size: 60px; line-height: 1.08; font-weight: 950; }
.inner-hero-grid > div > p { max-width: 760px; color: #38423d; font-size: 16px; }
.guide-index, .support-board { padding: 24px; border: 1px solid var(--ink); background: var(--white); box-shadow: 8px 8px 0 var(--ink); }
.guide-index strong, .support-board > b { display: block; padding-bottom: 14px; border-bottom: 1px solid var(--ink); font-size: 12px; }
.guide-index a { display: grid; grid-template-columns: 38px 1fr; gap: 8px; padding: 12px 0; border-bottom: 1px solid var(--line); font-size: 14px; font-weight: 750; }
.guide-index a:last-child { border: 0; }
.guide-index span { color: var(--coral); }
.article-section { padding: 82px 0; }
.alt-section { background: var(--white); }
.article-layout { display: grid; grid-template-columns: 160px minmax(0, 820px); gap: 72px; justify-content: center; }
.article-rail { align-self: stretch; display: flex; flex-direction: column; align-items: flex-start; border-right: 1px solid var(--ink); }
.article-rail span { display: grid; place-items: center; width: 58px; height: 58px; margin-bottom: 16px; background: var(--coral); border: 1px solid var(--ink); font-size: 20px; font-weight: 950; }
.article-rail b { font-size: 11px; writing-mode: vertical-rl; }
.prose h2 { margin-bottom: 26px; font-size: 40px; line-height: 1.2; }
.prose h3 { font-size: 18px; }
.prose p { color: #3e4943; }
.prose a:not(.button) { font-weight: 850; border-bottom: 1px solid var(--ink); }
.check-grid { display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 28px; border: 1px solid var(--ink); }
.check-grid div { padding: 18px; border-right: 1px solid var(--ink); }
.check-grid div:last-child { border: 0; }
.check-grid b, .check-grid span { display: block; }
.check-grid b { color: var(--coral); font-size: 12px; }
.check-grid span { font-size: 14px; font-weight: 800; }
.step-list { padding: 0; margin: 0 0 30px; list-style: none; border-top: 1px solid var(--ink); }
.step-list li { display: grid; grid-template-columns: 52px 1fr; gap: 22px; padding: 23px 0; border-bottom: 1px solid var(--ink); }
.step-list li > span { width: 36px; height: 36px; display: grid; place-items: center; background: var(--mint); border: 1px solid var(--ink); font-weight: 900; }
.step-list h3 { margin-bottom: 6px; }
.step-list p { margin: 0; }
.flow-row { display: grid; grid-template-columns: repeat(4, 1fr); margin: 28px 0; border: 1px solid var(--ink); }
.flow-row div { min-height: 205px; padding: 18px; border-right: 1px solid var(--ink); }
.flow-row div:last-child { border: 0; }
.flow-row span { color: var(--coral); font-size: 12px; font-weight: 900; }
.flow-row b { display: block; margin: 18px 0 8px; }
.flow-row p { margin: 0; font-size: 13px; }
.note-box { margin-top: 28px; padding: 23px; background: var(--yellow); border: 1px solid var(--ink); }
.note-box p { margin: 8px 0 0; }
.plain-list { padding: 0; list-style: none; border-top: 1px solid var(--ink); }
.plain-list li { padding: 16px 0; border-bottom: 1px solid var(--line); color: #3e4943; }

.faq-hero { background: var(--yellow); }
.support-board ol { padding: 0; margin: 10px 0 0; list-style: none; }
.support-board li { display: grid; grid-template-columns: 42px 1fr; padding: 11px 0; border-bottom: 1px solid var(--line); font-size: 14px; font-weight: 750; }
.support-board li:last-child { border: 0; }
.support-board span { color: var(--coral); }
.faq-main { padding-top: 70px; background: var(--white); }
.faq-columns { display: grid; grid-template-columns: 220px minmax(0, 820px); gap: 70px; justify-content: center; }
.faq-nav { position: sticky; top: 108px; align-self: start; display: flex; flex-direction: column; border-top: 1px solid var(--ink); }
.faq-nav .section-no { padding: 12px 0; border-bottom: 1px solid var(--ink); }
.faq-nav a { padding: 13px 0; border-bottom: 1px solid var(--line); font-size: 14px; font-weight: 800; }
.faq-group { margin-bottom: 70px; }
.group-title { display: flex; align-items: center; gap: 18px; padding-bottom: 18px; border-bottom: 2px solid var(--ink); }
.group-title span { display: grid; place-items: center; width: 42px; height: 42px; background: var(--mint); border: 1px solid var(--ink); font-weight: 900; }
.group-title h2 { margin: 0; font-size: 30px; }
.faq-content details { border-bottom: 1px solid var(--line); }
.faq-content summary { position: relative; padding: 20px 50px 20px 0; list-style: none; cursor: pointer; font-size: 17px; font-weight: 850; }
.faq-content summary::-webkit-details-marker { display: none; }
.faq-content summary::after { content: "+"; position: absolute; right: 12px; top: 15px; font-size: 24px; font-weight: 400; }
.faq-content details[open] summary::after { content: "−"; }
.faq-content details p { padding: 0 50px 22px 0; margin: 0; color: var(--muted); }
.next-help { display: flex; align-items: center; justify-content: space-between; gap: 32px; padding: 32px; background: var(--coral); border: 1px solid var(--ink); }
.next-help h2 { margin: 5px 0; }
.next-help p { margin: 0; }

@media (max-width: 980px) {
  :root { --header-height: 68px; }
  .header-inner, .section-inner, .hero-inner, .footer-inner { width: min(calc(100% - 32px), var(--container)); }
  .menu-toggle { display: flex; }
  .menu-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .menu-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
  .menu-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
  .site-nav { display: none; position: fixed; top: var(--header-height); left: 16px; right: 16px; padding: 12px; flex-direction: column; align-items: stretch; gap: 0; background: var(--paper); border: 1px solid var(--ink); box-shadow: 6px 6px 0 var(--ink); }
  .site-nav.open { display: flex; }
  .site-nav a { padding: 12px 10px; border-bottom: 1px solid var(--line); }
  .site-nav a::after { display: none; }
  .site-nav .nav-download { margin-top: 8px; text-align: center; }
  .hero-inner { min-height: 0; grid-template-columns: 1fr; gap: 36px; padding: 44px 0 38px; }
  .hero-copy { order: 1; }
  .hero-media { order: 2; max-width: 650px; margin: 0 auto; }
  .signal-grid { grid-template-columns: repeat(3, 1fr); padding: 12px 0; gap: 10px 0; }
  .gallery-grid { grid-template-columns: repeat(3, 1fr); }
  .gallery-frame, .gallery-featured .gallery-frame { height: 440px; }
  .feature-layout, .faq-preview-layout { grid-template-columns: 1fr; gap: 38px; }
  .vertical-heading { position: static; }
  .route-grid { grid-template-columns: 1fr; }
  .route-grid article { min-height: 0; border-right: 0; border-bottom: 1px solid var(--ink); }
  .route-index { margin-bottom: 22px; }
  .inner-hero-grid { grid-template-columns: 1fr; gap: 40px; }
  .article-layout { grid-template-columns: 80px minmax(0, 1fr); gap: 36px; }
  .faq-columns { grid-template-columns: 170px minmax(0, 1fr); gap: 40px; }
  .flow-row { grid-template-columns: repeat(2, 1fr); }
  .flow-row div:nth-child(2) { border-right: 0; }
  .flow-row div:nth-child(-n+2) { border-bottom: 1px solid var(--ink); }
}

@media (max-width: 680px) {
  .header-inner, .section-inner, .hero-inner, .footer-inner { width: min(calc(100% - 28px), var(--container)); }
  .brand { font-size: 17px; }
  .brand img { width: 40px; height: 40px; }
  .hero-inner { padding: 28px 0 26px; gap: 24px; }
  .eyebrow { margin-bottom: 18px; }
  .hero h1 { font-size: 39px; line-height: 1.08; margin-bottom: 18px; }
  .hero-copy > p { font-size: 14px; line-height: 1.75; margin-bottom: 20px; }
  .hero-actions { margin-bottom: 20px; }
  .button { min-height: 44px; padding: 10px 16px; font-size: 14px; }
  .hero-facts { display: none; }
  .hero-media { height: 294px; border: 0; background: none; }
  .media-label { display: none; }
  .phone-shot { box-shadow: 5px 5px 0 var(--ink); }
  .shot-main { width: 138px; left: calc(50% - 69px); top: 25px; }
  .shot-side { width: 87px; }
  .shot-side-top { left: 3px; right: auto; top: 24px; }
  .shot-side-bottom { right: 3px; bottom: 8px; }
  .phone-shot figcaption { padding: 3px 4px; font-size: 8px; }
  .signal-strip { display: none; }
  .section { padding: 64px 0; }
  .section-heading { display: block; margin-bottom: 28px; }
  .section-heading h2 { font-size: 34px; }
  .section-heading > p { margin-top: 14px; font-size: 14px; }
  .gallery-grid { grid-template-columns: 1fr; gap: 30px; }
  .gallery-frame, .gallery-featured .gallery-frame { height: 430px; }
  .feature-list article { grid-template-columns: 42px 1fr; gap: 12px; }
  .route-grid article { padding: 22px; }
  .download-band { padding: 52px 0; }
  .download-inner { display: block; }
  .download-inner h2 { font-size: 33px; }
  .download-inner .button { margin-top: 22px; }
  .footer-inner { grid-template-columns: 1fr; text-align: center; }
  .footer-brand, .footer-inner nav { justify-content: center; }
  .footer-inner nav { flex-wrap: wrap; }
  .disclaimer, .copyright { grid-column: auto; }
  .inner-hero { padding: 52px 0; }
  .inner-hero h1 { font-size: 42px; }
  .inner-hero-grid { gap: 30px; }
  .article-section { padding: 58px 0; }
  .article-layout { grid-template-columns: 1fr; gap: 18px; }
  .article-rail { border-right: 0; border-bottom: 1px solid var(--ink); flex-direction: row; align-items: center; gap: 12px; padding-bottom: 12px; }
  .article-rail span { width: 42px; height: 42px; margin: 0; }
  .article-rail b { writing-mode: horizontal-tb; }
  .prose h2 { font-size: 32px; }
  .check-grid, .flow-row { grid-template-columns: 1fr; }
  .check-grid div, .flow-row div { min-height: 0; border-right: 0; border-bottom: 1px solid var(--ink); }
  .check-grid div:last-child, .flow-row div:last-child { border-bottom: 0; }
  .step-list li { grid-template-columns: 42px 1fr; gap: 12px; }
  .faq-columns { grid-template-columns: 1fr; }
  .faq-nav { position: static; display: grid; grid-template-columns: repeat(2, 1fr); border: 1px solid var(--ink); }
  .faq-nav .section-no { grid-column: 1 / -1; padding-left: 12px; }
  .faq-nav a { padding: 11px 12px; border-right: 1px solid var(--line); }
  .faq-group { margin-bottom: 52px; }
  .group-title h2 { font-size: 26px; }
  .faq-content summary { font-size: 15px; }
  .next-help { display: block; padding: 24px; }
  .next-help .button { margin-top: 22px; }
}

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