:root {
  --ink: #18222b;
  --muted: #5f6b72;
  --paper: #f7f8f6;
  --white: #ffffff;
  --line: #d9dfdc;
  --coral: #f2594b;
  --coral-dark: #c83e35;
  --jade: #1f8976;
  --yellow: #f3c64e;
  --container: 1180px;
}

* { 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;
  letter-spacing: 0;
  line-height: 1.7;
}
body.nav-open { overflow: hidden; }
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; height: auto; }
button, a { -webkit-tap-highlight-color: transparent; }
p { margin: 0; color: var(--muted); }
h1, h2, h3, dl, dd, figure { margin: 0; }

.header-inner, .hero-inner, .section-inner, .article-inner {
  width: min(calc(100% - 48px), var(--container));
  margin-inline: auto;
}
.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  background: rgba(247, 248, 246, 0.96);
  border-bottom: 1px solid var(--line);
}
.header-inner { height: 72px; display: flex; align-items: center; justify-content: space-between; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-size: 18px; font-weight: 800; }
.brand img { width: 38px; height: 38px; object-fit: cover; border-radius: 6px; }
.site-nav { display: flex; align-items: center; gap: 28px; font-size: 14px; font-weight: 650; }
.site-nav > a:not(.nav-download) { padding: 22px 0 18px; border-bottom: 3px solid transparent; }
.site-nav > a:hover, .site-nav > a.is-active { color: var(--coral-dark); border-color: var(--coral); }
.nav-download { padding: 9px 20px; color: var(--white); background: var(--ink); border: 1px solid var(--ink); border-radius: 4px; }
.nav-download:hover { color: var(--white); background: var(--coral-dark); border-color: var(--coral-dark); }
.menu-toggle { display: none; width: 42px; height: 42px; border: 1px solid var(--line); background: var(--white); color: var(--ink); font-size: 22px; border-radius: 4px; cursor: pointer; }

.hero { background: var(--white); border-bottom: 1px solid var(--line); }
.hero-inner { min-height: 690px; display: grid; grid-template-columns: minmax(0, 1.08fr) minmax(430px, .92fr); align-items: center; gap: 70px; padding-block: 44px; }
.eyebrow { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.eyebrow span { padding: 4px 9px; border: 1px solid var(--line); color: var(--jade); background: var(--paper); font-size: 12px; font-weight: 750; border-radius: 3px; }
.hero h1 { max-width: 620px; font-size: 58px; line-height: 1.08; font-weight: 900; }
.hero h1 span { display: block; }
.hero h1 span:last-child { color: var(--coral); }
.hero-copy > p { max-width: 620px; margin-top: 22px; font-size: 17px; line-height: 1.85; }
.hero-actions { display: flex; align-items: center; gap: 22px; margin-top: 28px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: 10px 26px; font-weight: 800; border-radius: 4px; transition: background .2s ease, transform .2s ease; }
.button:hover { transform: translateY(-2px); }
.button-primary { color: var(--white); background: var(--coral); border: 1px solid var(--coral); }
.button-primary:hover { background: var(--coral-dark); }
.button-light { color: var(--ink); background: var(--white); border: 1px solid var(--white); }
.text-link { color: var(--ink); font-weight: 800; text-decoration: underline; text-decoration-color: var(--yellow); text-decoration-thickness: 3px; text-underline-offset: 5px; }
.hero-facts { display: grid; grid-template-columns: repeat(3, 1fr); max-width: 520px; margin-top: 38px; border-top: 1px solid var(--line); }
.hero-facts div { padding: 16px 14px 0 0; }
.hero-facts dt { color: var(--coral); font-size: 12px; font-weight: 900; }
.hero-facts dd { margin-top: 2px; font-size: 14px; font-weight: 750; }

.hero-media { position: relative; min-height: 440px; display: grid; grid-template-columns: 1fr 1fr; align-items: start; gap: 20px; padding: 20px 18px 60px; border-left: 1px solid var(--line); }
.portrait { position: relative; max-width: 188px; padding: 9px; background: var(--white); border: 1px solid var(--ink); box-shadow: 9px 9px 0 var(--yellow); }
.portrait img { width: 100%; max-width: 400px; }
.portrait-secondary { margin-top: 44px; box-shadow: 9px 9px 0 var(--jade); }
.media-index { position: absolute; top: -18px; left: -1px; padding: 2px 8px; color: var(--white); background: var(--ink); font-size: 12px; font-weight: 800; }
.media-strip { position: absolute; right: 0; bottom: 0; width: 228px; display: grid; grid-template-columns: 68px 1fr; align-items: center; gap: 8px; padding: 7px; background: var(--white); border: 1px solid var(--line); }
.media-strip span { color: var(--muted); font-size: 11px; font-weight: 800; text-align: center; }
.media-strip img { width: 145px; max-width: 400px; }

.section { padding: 84px 0; }
.section + .section { border-top: 1px solid var(--line); }
.section-heading { display: flex; align-items: baseline; gap: 18px; margin-bottom: 38px; }
.section-heading h2 { font-size: 34px; line-height: 1.2; }
.section-number { min-width: 64px; color: var(--coral); font-size: 12px; font-weight: 900; }
.interface-section { background: var(--paper); }
.interface-grid { display: grid; grid-template-columns: .78fr 1.2fr .78fr; align-items: end; gap: 34px; }
.screen-figure { display: flex; flex-direction: column; gap: 16px; }
.screen-figure img { width: 100%; max-width: 400px; margin-inline: auto; object-fit: contain; border: 1px solid var(--line); box-shadow: 10px 10px 0 var(--ink); }
.screen-figure.wide img { max-width: 400px; }
.screen-figure figcaption { display: grid; gap: 3px; padding-top: 12px; border-top: 3px solid var(--yellow); }
.screen-figure figcaption strong { font-size: 16px; }
.screen-figure figcaption span { color: var(--muted); font-size: 13px; }

.features-section { background: var(--white); }
.feature-table { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.feature-table article { min-height: 232px; padding: 24px; border-right: 1px solid var(--line); }
.feature-table article:last-child { border-right: 0; }
.feature-id { color: var(--coral); font-size: 38px; font-weight: 900; }
.feature-table h3 { margin-top: 32px; font-size: 20px; }
.feature-table p { margin-top: 8px; font-size: 14px; }

.path-section { background: var(--ink); color: var(--white); }
.path-layout { display: grid; grid-template-columns: 280px 1fr; gap: 72px; }
.vertical-heading { align-items: flex-start; flex-direction: column; margin: 0; }
.vertical-heading h2 { font-size: 42px; }
.path-list { list-style: none; margin: 0; padding: 0; border-top: 1px solid #46505a; }
.path-list li { display: grid; grid-template-columns: 72px 1fr; gap: 20px; padding: 22px 0; border-bottom: 1px solid #46505a; }
.path-list > li > span { color: var(--yellow); font-size: 14px; font-weight: 900; }
.path-list h3 { font-size: 19px; }
.path-list p { margin-top: 4px; color: #bac3c7; }

.routes-section { background: var(--paper); }
.route-grid { display: grid; grid-template-columns: 1fr 1fr; border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.route-link { position: relative; min-height: 190px; display: flex; flex-direction: column; justify-content: center; gap: 8px; padding: 28px 74px 28px 28px; }
.route-link + .route-link { border-left: 1px solid var(--ink); }
.route-link > span:first-child { color: var(--jade); font-size: 13px; font-weight: 800; }
.route-link strong { font-size: 24px; }
.route-arrow { position: absolute; right: 28px; font-size: 28px; }
.route-link:hover { background: var(--white); }

.faq-preview-section { background: var(--white); }
.faq-preview { border-top: 1px solid var(--ink); }
details { border-bottom: 1px solid var(--line); }
summary { position: relative; padding: 20px 46px 20px 0; font-weight: 800; cursor: pointer; list-style: none; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; position: absolute; right: 8px; top: 16px; color: var(--coral); font-size: 24px; }
details[open] summary::after { content: "−"; }
details > p, details > div { padding: 0 46px 20px 0; }
.faq-more { display: inline-block; margin-top: 28px; }

.download-band { padding: 54px 0; color: var(--white); background: var(--coral); }
.download-band-inner { display: flex; align-items: center; justify-content: space-between; gap: 28px; }
.download-band span { font-size: 13px; font-weight: 800; }
.download-band h2 { margin-top: 4px; font-size: 30px; }
.site-footer { padding: 36px 0; background: var(--ink); color: var(--white); text-align: center; }
.site-footer nav { display: flex; justify-content: center; gap: 24px; font-size: 13px; }
.site-footer p { max-width: 820px; margin: 16px auto 8px; color: #bcc5c9; font-size: 12px; text-align: center; }
.site-footer small { color: #929da3; text-align: center; }

.inner-hero { padding: 76px 0 68px; background: var(--white); border-bottom: 1px solid var(--line); }
.inner-hero-grid { display: grid; grid-template-columns: 1.2fr .8fr; gap: 80px; align-items: center; }
.inner-hero h1 { max-width: 720px; font-size: 48px; line-height: 1.15; }
.inner-hero p { max-width: 690px; margin-top: 18px; font-size: 16px; }
.inner-hero .button { margin-top: 26px; }
.guide-index { border-top: 1px solid var(--ink); }
.guide-index a { display: grid; grid-template-columns: 44px 1fr; padding: 12px 0; border-bottom: 1px solid var(--line); font-weight: 750; }
.guide-index span { color: var(--coral); font-size: 12px; }

.article-section { padding: 72px 0; scroll-margin-top: 80px; background: var(--white); }
.article-section.shaded { background: var(--paper); }
.article-inner { display: grid; grid-template-columns: 280px 1fr; gap: 72px; }
.article-marker span { color: var(--coral); font-size: 12px; font-weight: 900; }
.article-marker h2 { margin-top: 8px; font-size: 30px; }
.article-copy { max-width: 760px; }
.article-copy > p + p { margin-top: 16px; }
.article-copy a { color: var(--coral-dark); font-weight: 800; }
.check-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 26px; }
.check-row strong, .check-row span { padding: 8px 12px; border: 1px solid var(--line); background: var(--white); font-size: 13px; border-radius: 3px; }
.check-row strong { color: var(--white); background: var(--ink); border-color: var(--ink); }
.instruction-list { list-style: none; margin: 28px 0 0; padding: 0; border-top: 1px solid var(--line); }
.instruction-list li { display: grid; grid-template-columns: 40px 1fr; gap: 16px; padding: 18px 0; border-bottom: 1px solid var(--line); }
.instruction-list > li > span { color: var(--coral); font-size: 22px; font-weight: 900; }
.instruction-list p { margin-top: 3px; }
.reading-flow { display: grid; grid-template-columns: repeat(5, 1fr); margin-top: 28px; border: 1px solid var(--ink); }
.reading-flow span { position: relative; padding: 14px 12px; border-right: 1px solid var(--line); font-size: 13px; font-weight: 800; text-align: center; }
.reading-flow span:last-child { border-right: 0; }
.article-copy .text-link { display: inline-block; margin-top: 24px; color: var(--ink); }

.faq-signal { display: grid; grid-template-columns: 1fr auto 1fr auto 1fr auto 1fr; align-items: center; border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.faq-signal span { padding: 20px 8px; font-size: 13px; font-weight: 800; text-align: center; }
.faq-signal i { color: var(--coral); font-style: normal; }
.faq-main { padding: 72px 0 90px; background: var(--paper); }
.faq-layout { display: grid; grid-template-columns: 230px 1fr; gap: 64px; align-items: start; }
.faq-aside { position: sticky; top: 100px; display: flex; flex-direction: column; border-top: 1px solid var(--ink); }
.faq-aside > span { padding: 14px 0; color: var(--coral); font-size: 12px; font-weight: 900; }
.faq-aside a { padding: 10px 0; border-top: 1px solid var(--line); font-size: 14px; font-weight: 750; }
.faq-aside .text-link { margin-top: 18px; border-top: 0; }
.faq-group { scroll-margin-top: 90px; margin-bottom: 58px; }
.faq-group-title { display: flex; align-items: baseline; gap: 18px; padding-bottom: 18px; border-bottom: 1px solid var(--ink); }
.faq-group-title span { color: var(--coral); font-size: 12px; font-weight: 900; }
.faq-group-title h2 { font-size: 28px; }
.faq-content details > div p { max-width: 760px; }

@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr 380px; gap: 30px; }
  .hero h1 { font-size: 48px; }
  .hero-media { min-height: 400px; }
  .feature-table { grid-template-columns: 1fr 1fr; }
  .feature-table article:nth-child(2) { border-right: 0; }
  .feature-table article:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .article-inner { grid-template-columns: 220px 1fr; gap: 40px; }
}

@media (max-width: 760px) {
  .header-inner, .hero-inner, .section-inner, .article-inner { width: min(calc(100% - 32px), var(--container)); }
  .header-inner { height: 64px; }
  .brand img { width: 34px; height: 34px; }
  .menu-toggle { display: inline-grid; place-items: center; }
  .site-nav { position: fixed; inset: 64px 0 auto; display: none; flex-direction: column; align-items: stretch; gap: 0; padding: 14px 16px 22px; background: var(--white); border-bottom: 1px solid var(--line); box-shadow: 0 16px 30px rgba(24, 34, 43, .12); }
  .site-nav.is-open { display: flex; }
  .site-nav > a:not(.nav-download) { padding: 13px 4px; border-bottom: 1px solid var(--line); }
  .nav-download { margin-top: 12px; text-align: center; }
  .hero-inner { min-height: 718px; grid-template-columns: 1fr; align-content: start; gap: 24px; padding-block: 28px 22px; }
  .hero h1 { font-size: 40px; }
  .hero-copy > p { margin-top: 14px; font-size: 15px; line-height: 1.75; }
  .hero-actions { margin-top: 20px; }
  .hero-facts { display: none; }
  .hero-media { min-height: 286px; width: 100%; max-width: 430px; grid-template-columns: 1fr 1fr; gap: 16px; padding: 14px 10px 34px; border-left: 0; border-top: 1px solid var(--line); }
  .portrait { max-width: 122px; padding: 6px; justify-self: center; box-shadow: 6px 6px 0 var(--yellow); }
  .portrait-secondary { margin-top: 22px; box-shadow: 6px 6px 0 var(--jade); }
  .media-index { top: -14px; }
  .media-strip { right: 0; bottom: 0; width: 154px; grid-template-columns: 48px 1fr; padding: 4px; }
  .media-strip img { width: 96px; }
  .media-strip span { font-size: 10px; }
  .section { padding: 58px 0; }
  .section-heading { margin-bottom: 28px; }
  .section-heading h2 { font-size: 28px; }
  .interface-grid { grid-template-columns: 1fr 1fr; align-items: start; gap: 28px 18px; }
  .screen-figure.wide { grid-column: 1 / -1; grid-row: 2; }
  .screen-figure.wide img { width: min(100%, 400px); }
  .screen-figure figcaption span { font-size: 12px; }
  .feature-table { grid-template-columns: 1fr; }
  .feature-table article, .feature-table article:nth-child(2) { min-height: auto; border-right: 0; border-bottom: 1px solid var(--line); }
  .feature-table article:last-child { border-bottom: 0; }
  .feature-table h3 { margin-top: 12px; }
  .path-layout { grid-template-columns: 1fr; gap: 28px; }
  .vertical-heading { flex-direction: row; align-items: baseline; }
  .vertical-heading h2 { font-size: 30px; }
  .path-list li { grid-template-columns: 48px 1fr; }
  .route-grid { grid-template-columns: 1fr; }
  .route-link { min-height: 150px; }
  .route-link + .route-link { border-left: 0; border-top: 1px solid var(--ink); }
  .download-band-inner { align-items: flex-start; flex-direction: column; }
  .download-band h2 { font-size: 25px; }
  .inner-hero { padding: 50px 0; }
  .inner-hero-grid { grid-template-columns: 1fr; gap: 36px; }
  .inner-hero h1 { font-size: 34px; }
  .article-inner { grid-template-columns: 1fr; gap: 24px; }
  .article-section { padding: 54px 0; }
  .reading-flow { grid-template-columns: 1fr; }
  .reading-flow span { border-right: 0; border-bottom: 1px solid var(--line); }
  .reading-flow span:last-child { border-bottom: 0; }
  .faq-signal { grid-template-columns: 1fr; }
  .faq-signal i { transform: rotate(90deg); text-align: center; }
  .faq-signal span { padding: 10px; }
  .faq-layout { grid-template-columns: 1fr; gap: 38px; }
  .faq-aside { position: static; }
  .faq-main { padding: 54px 0 70px; }
}

@media (max-width: 390px) {
  .hero h1 { font-size: 37px; }
  .hero-actions { gap: 16px; }
  .button { padding-inline: 21px; }
  .interface-grid { gap: 26px 14px; }
}