:root {
  --navy: #17355f;
  --navy-dark: #102641;
  --blue: #2677d8;
  --coral: #d45f4b;
  --ice: #eef6fc;
  --paper: #ffffff;
  --ink: #17202d;
  --muted: #5d6878;
  --line: #dbe3ec;
  --shadow: 0 18px 45px rgba(25, 53, 86, 0.12);
}

* { 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: 1.72;
}
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button, a { -webkit-tap-highlight-color: transparent; }
.section-inner, .header-inner, .hero-inner, .footer-inner { width: min(1160px, calc(100% - 48px)); margin: 0 auto; }

.site-header { position: sticky; top: 0; z-index: 30; min-height: 72px; background: rgba(255,255,255,0.96); border-bottom: 1px solid var(--line); backdrop-filter: blur(14px); }
.header-inner { min-height: 72px; display: flex; align-items: center; gap: 28px; }
.brand { display: inline-flex; align-items: center; gap: 10px; flex: 0 0 auto; font-weight: 800; color: var(--navy-dark); }
.brand img { width: 42px; height: 42px; border-radius: 8px; }
.site-nav { display: flex; align-items: center; gap: 6px; margin-left: auto; }
.site-nav a { padding: 8px 12px; color: var(--muted); font-size: 15px; border-bottom: 2px solid transparent; }
.site-nav a:hover, .site-nav a.active { color: var(--navy); border-color: var(--coral); }
.header-actions, .hero-actions, .download-actions { display: flex; gap: 10px; align-items: center; }
.button { min-height: 42px; padding: 9px 18px; display: inline-flex; align-items: center; justify-content: center; border: 1px solid transparent; border-radius: 6px; font-weight: 700; font-size: 14px; line-height: 1.2; transition: transform .2s ease, box-shadow .2s ease, background .2s ease; }
.button:hover { transform: translateY(-1px); }
.button-primary { color: #fff; background: var(--navy); box-shadow: 0 8px 20px rgba(23,53,95,.18); }
.button-ghost { color: var(--navy); border-color: #b9c9dc; background: #fff; }
.button-ios { color: var(--navy); border-color: #9fb5cf; background: var(--ice); }
.button-large { min-height: 50px; padding: 13px 24px; font-size: 16px; }
.menu-button { display: none; width: 42px; height: 42px; padding: 10px; border: 1px solid var(--line); background: #fff; border-radius: 6px; }
.menu-button span { display: block; height: 2px; margin: 4px 0; background: var(--navy); }

.hero { background: linear-gradient(110deg, #f8fbfe 0%, #eef6fc 64%, #fdf6f3 100%); border-bottom: 1px solid var(--line); }
.hero-inner { min-height: 640px; display: grid; grid-template-columns: minmax(0, 1.08fr) minmax(360px, .92fr); align-items: center; gap: 68px; padding: 56px 0; }
.eyebrow { color: var(--coral); font-size: 13px; font-weight: 800; letter-spacing: 0; margin-bottom: 14px; }
h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 20px; color: var(--navy-dark); font-size: clamp(38px, 4vw, 58px); line-height: 1.16; letter-spacing: 0; }
.hero-copy > p { max-width: 650px; margin-bottom: 26px; color: #475569; font-size: 17px; }
.quick-specs { margin: 30px 0 0; display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid #c8d7e7; }
.quick-specs div { padding: 16px 10px 0 0; }
.quick-specs dt { color: var(--muted); font-size: 12px; }
.quick-specs dd { margin: 2px 0 0; color: var(--navy-dark); font-weight: 800; }
.hero-media { position: relative; min-height: 480px; display: flex; align-items: center; justify-content: center; border-left: 1px solid #bdccdd; }
.hero-media img { width: 245px; max-width: 400px; max-height: 436px; object-fit: contain; border-radius: 8px; box-shadow: var(--shadow); }
.media-index { position: absolute; left: 16px; top: 20px; display: grid; color: var(--navy); }
.media-index span:first-child { color: var(--coral); font-size: 30px; font-weight: 800; line-height: 1; }
.media-index span:last-child { margin-top: 8px; font-size: 12px; writing-mode: vertical-rl; letter-spacing: 0; }

.section { padding: 88px 0; }
.section-heading { display: flex; align-items: end; justify-content: space-between; margin-bottom: 34px; }
.section-heading h2, .scenario-title h2 { margin: 0; color: var(--navy-dark); font-size: clamp(28px, 3vw, 40px); line-height: 1.25; }
.section-heading h2::after { content: ""; display: block; width: 48px; height: 3px; margin-top: 13px; background: var(--coral); }
.section-gallery { background: #fff; }
.gallery-rail { display: grid; grid-template-columns: 1.08fr .92fr; gap: 24px; }
.gallery-featured, .gallery-list figure { margin: 0; background: var(--ice); border: 1px solid var(--line); border-radius: 8px; overflow: hidden; }
.gallery-featured { display: grid; grid-template-columns: 1fr 1fr; align-items: center; min-height: 520px; padding: 32px; }
.gallery-featured img { width: 250px; max-width: 400px; margin: 0 auto; border-radius: 8px; box-shadow: var(--shadow); }
figcaption { display: grid; gap: 6px; }
figcaption strong { color: var(--navy-dark); font-size: 19px; }
figcaption span { color: var(--muted); font-size: 14px; }
.gallery-list { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.gallery-list figure { display: flex; flex-direction: column; justify-content: space-between; padding: 24px; background: #fff; }
.gallery-list img { width: 175px; max-height: 312px; object-fit: contain; margin: 0 auto 20px; border-radius: 7px; box-shadow: 0 12px 28px rgba(22,48,79,.11); }

.section-features { background: #f7f9fc; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.feature-grid article { min-height: 250px; padding: 26px 22px; background: #fff; border: 1px solid var(--line); border-radius: 8px; }
.feature-no { color: var(--coral); font-size: 13px; font-weight: 800; }
.feature-grid h3 { margin: 30px 0 12px; color: var(--navy-dark); font-size: 20px; }
.feature-grid p { margin: 0; color: var(--muted); font-size: 15px; }
.scenario-layout { display: grid; grid-template-columns: .72fr 1.28fr; gap: 72px; }
.scenario-title { padding-right: 28px; border-right: 1px solid var(--line); }
.scenario-copy { margin-top: 22px; color: var(--muted); }
.scenario-notes { display: grid; gap: 4px; }
.scenario-notes article { padding: 20px 0; border-bottom: 1px solid var(--line); }
.scenario-notes article:first-child { padding-top: 0; }
.scenario-notes h3 { margin-bottom: 6px; color: var(--navy); font-size: 18px; }
.scenario-notes p { margin: 0; color: var(--muted); }
.section-steps { background: var(--ice); }
.step-list { margin: 0 0 28px; padding: 0; list-style: none; display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.step-list li { display: flex; gap: 18px; padding: 24px; background: #fff; border: 1px solid var(--line); border-radius: 8px; }
.step-list li > span { flex: 0 0 auto; color: var(--coral); font-size: 24px; font-weight: 800; }
.step-list h3 { margin-bottom: 8px; font-size: 18px; }
.step-list p { margin: 0; color: var(--muted); font-size: 14px; }
.text-link { display: inline-flex; color: var(--navy); font-weight: 800; border-bottom: 1px solid var(--coral); }
.faq-preview-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-bottom: 26px; }
.faq-preview-grid article { padding: 24px; border: 1px solid var(--line); border-radius: 8px; }
.faq-preview-grid h3 { color: var(--navy-dark); font-size: 18px; }
.faq-preview-grid p { margin: 0; color: var(--muted); font-size: 14px; }

.download-band { padding: 48px 0; color: #fff; background: var(--navy); }
.download-band-inner { display: flex; align-items: center; justify-content: space-between; gap: 32px; }
.download-band h2 { margin-bottom: 8px; font-size: 30px; }
.download-band p { margin: 0; color: #d8e5f4; }
.download-copy { color: #d8e5f4; }
.button-light { color: var(--navy-dark); background: #fff; }
.button-outline-light { color: #fff; border-color: #b7c9df; }
.site-footer { padding: 28px 0; color: var(--muted); background: #f5f7fa; border-top: 1px solid var(--line); text-align: center; }
.footer-inner p { margin: 4px 0; font-size: 13px; }

.subpage-hero, .faq-hero { background: var(--ice); border-bottom: 1px solid var(--line); }
.subpage-hero-inner { min-height: 470px; display: grid; grid-template-columns: 1fr 280px; align-items: center; gap: 80px; padding: 44px 0; }
.subpage-hero h1, .faq-hero h1 { font-size: clamp(34px, 4vw, 52px); }
.subpage-hero p, .faq-hero p { max-width: 720px; color: var(--muted); font-size: 17px; }
.subpage-hero img { width: 170px; max-height: 330px; object-fit: contain; margin: 0 auto; border-radius: 8px; box-shadow: var(--shadow); }
.article-shell { display: grid; grid-template-columns: 220px 1fr; gap: 60px; padding-top: 72px; padding-bottom: 88px; }
.article-nav { position: sticky; top: 104px; align-self: start; display: grid; gap: 10px; padding: 20px; border-left: 3px solid var(--coral); background: #f7f9fc; }
.article-nav strong { margin-bottom: 6px; color: var(--navy-dark); }
.article-nav a { color: var(--muted); font-size: 14px; }
.article-nav a:hover { color: var(--navy); }
.article-content > section { padding: 0 0 44px; margin-bottom: 44px; border-bottom: 1px solid var(--line); }
.article-content h2 { color: var(--navy-dark); font-size: 28px; }
.article-content p { color: #465363; }
.article-content a { color: var(--blue); font-weight: 700; }
.article-kicker { color: var(--coral); font-weight: 800; }
.article-download { display: flex; justify-content: space-between; gap: 30px; align-items: center; padding: 30px; background: var(--ice); border: 1px solid var(--line); border-radius: 8px; }
.article-download h2 { margin-bottom: 4px; font-size: 24px; }
.article-download p { margin: 0; }
.article-download > div:last-child { display: flex; gap: 10px; }

.faq-hero { padding: 78px 0 64px; }
.faq-hero h1 { margin-bottom: 16px; }
.faq-layout { display: grid; grid-template-columns: 300px 1fr; gap: 64px; align-items: start; }
.faq-intro { position: sticky; top: 104px; padding: 24px; background: var(--ice); border-radius: 8px; }
.faq-intro h2 { color: var(--navy-dark); font-size: 24px; }
.faq-intro ol { padding-left: 20px; color: var(--muted); }
.faq-intro img { width: 160px; max-height: 285px; object-fit: contain; margin: 24px auto 0; border-radius: 7px; box-shadow: var(--shadow); }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary { position: relative; padding: 20px 48px 20px 0; color: var(--navy-dark); font-weight: 800; cursor: pointer; list-style: none; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; position: absolute; right: 6px; top: 16px; color: var(--coral); font-size: 24px; }
.faq-list details[open] summary::after { content: "−"; }
.faq-list details p { margin: 0; padding: 0 48px 20px 0; color: var(--muted); }
.faq-next { margin-top: 38px; padding: 28px; background: #f7f9fc; border-left: 3px solid var(--coral); }
.faq-next h2 { margin-bottom: 8px; color: var(--navy-dark); font-size: 24px; }

@media (max-width: 980px) {
  .header-actions { display: none; }
  .feature-grid { grid-template-columns: 1fr 1fr; }
  .gallery-rail { grid-template-columns: 1fr; }
  .gallery-featured { min-height: 440px; }
  .scenario-layout { grid-template-columns: 1fr; gap: 36px; }
  .scenario-title { border-right: 0; border-bottom: 1px solid var(--line); padding: 0 0 24px; }
}

@media (max-width: 760px) {
  .section-inner, .header-inner, .hero-inner, .footer-inner { width: min(100% - 32px, 1160px); }
  .site-header, .header-inner { min-height: 64px; }
  .brand img { width: 38px; height: 38px; }
  .menu-button { display: block; margin-left: auto; }
  .site-nav { display: none; position: absolute; left: 16px; right: 16px; top: 70px; padding: 10px; background: #fff; border: 1px solid var(--line); border-radius: 8px; box-shadow: var(--shadow); }
  .site-nav.open { display: grid; }
  .site-nav a { padding: 12px; border-bottom: 0; }
  .hero-inner { min-height: 0; grid-template-columns: 1fr; gap: 22px; padding: 30px 0 26px; }
  h1 { font-size: 36px; line-height: 1.2; }
  .hero-copy > p { margin-bottom: 20px; font-size: 15px; }
  .hero-actions { align-items: stretch; }
  .hero-actions .button { flex: 1; padding-left: 12px; padding-right: 12px; }
  .quick-specs { margin-top: 20px; }
  .quick-specs dd { font-size: 13px; }
  .hero-media { min-height: 276px; border-left: 0; border-top: 1px solid #bdccdd; padding-top: 0; }
  .hero-media img { width: 154px; max-height: 274px; }
  .media-index { left: 0; top: 20px; }
  .media-index span:first-child { font-size: 22px; }
  .section { padding: 60px 0; }
  .gallery-featured { grid-template-columns: 1fr; min-height: 0; gap: 24px; padding: 24px; }
  .gallery-featured img { width: 175px; }
  .gallery-list { grid-template-columns: 1fr 1fr; gap: 12px; }
  .gallery-list figure { padding: 16px; }
  .gallery-list img { width: 120px; max-height: 214px; }
  figcaption strong { font-size: 16px; }
  .feature-grid, .step-list, .faq-preview-grid { grid-template-columns: 1fr; }
  .feature-grid article { min-height: 0; }
  .download-band-inner, .article-download { align-items: flex-start; flex-direction: column; }
  .download-actions, .article-download > div:last-child { width: 100%; }
  .download-actions .button, .article-download .button { flex: 1; }
  .subpage-hero-inner { min-height: 0; grid-template-columns: 1fr; gap: 20px; padding: 38px 0; }
  .subpage-hero h1 { font-size: 28px; }
  .subpage-hero img { width: 125px; max-height: 224px; }
  .article-shell, .faq-layout { grid-template-columns: 1fr; gap: 36px; padding-top: 52px; }
  .article-nav, .faq-intro { position: static; }
  .article-nav { grid-template-columns: 1fr 1fr; }
  .article-nav strong { grid-column: 1 / -1; }
  .faq-hero { padding: 48px 0 38px; }
  .faq-intro img { width: 130px; max-height: 232px; }
}

@media (max-width: 430px) {
  .brand span { font-size: 15px; }
  h1 { font-size: 32px; }
  .gallery-list { grid-template-columns: 1fr; }
  .gallery-list figure { flex-direction: row; align-items: center; gap: 18px; }
  .gallery-list img { width: 98px; margin: 0; }
  .quick-specs { gap: 6px; }
  .button { font-size: 13px; }
}