:root {
  --graphite: #27313d;
  --graphite-deep: #19212b;
  --blue: #3b6f9e;
  --blue-soft: #eaf1f7;
  --paper: #ffffff;
  --wash: #f5f7f9;
  --ink: #202934;
  --muted: #626e7c;
  --line: #d9e0e7;
  --alert: #b95645;
  --shadow: 0 16px 38px rgba(31, 45, 61, .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: 1.7; }
img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }
.header-rail, .overview-grid, .module-rail, .final-banner-inner, .footer-rail, .manual-head-rail, .manual-layout, .faq-title-rail, .faq-content-rail { width: min(1140px, calc(100% - 48px)); margin: 0 auto; }

.header { position: sticky; top: 0; z-index: 20; min-height: 70px; background: rgba(255,255,255,.97); border-bottom: 1px solid var(--line); backdrop-filter: blur(12px); }
.header-rail { min-height: 70px; display: flex; align-items: center; gap: 28px; }
.identity { display: flex; align-items: center; gap: 10px; color: var(--graphite-deep); font-weight: 800; }
.identity img { width: 42px; height: 42px; border-radius: 6px; }
.navigation { display: flex; gap: 6px; margin-left: auto; }
.navigation a { padding: 8px 13px; color: var(--muted); font-size: 14px; border-radius: 5px; }
.navigation a:hover, .navigation a.selected { color: var(--graphite-deep); background: var(--blue-soft); }
.header-links, .overview-actions, .final-banner-inner > div:last-child, .manual-download > div { display: flex; align-items: center; gap: 10px; }
.control { min-height: 42px; display: inline-flex; align-items: center; justify-content: center; padding: 9px 18px; border: 1px solid transparent; border-radius: 5px; font-size: 14px; font-weight: 800; line-height: 1.2; transition: transform .2s ease, box-shadow .2s ease; }
.control:hover { transform: translateY(-1px); }
.control-dark { color: #fff; background: var(--graphite); box-shadow: 0 8px 18px rgba(39,49,61,.18); }
.control-ios { color: var(--graphite); border-color: #aebdcb; background: #fff; }
.control-large { min-height: 50px; padding: 13px 25px; font-size: 16px; }
.nav-toggle { display: none; width: 42px; height: 42px; padding: 9px 10px; border: 1px solid var(--line); border-radius: 5px; background: #fff; }
.nav-toggle i { display: block; height: 2px; margin: 4px 0; background: var(--graphite); }

.overview-hero { background: var(--wash); border-bottom: 1px solid var(--line); }
.overview-grid { min-height: 640px; display: grid; grid-template-columns: 1.05fr .95fr; gap: 68px; align-items: center; padding: 48px 0; }
.section-code { display: inline-flex; margin-bottom: 14px; color: var(--alert); font-size: 12px; font-weight: 800; }
h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 20px; color: var(--graphite-deep); font-size: clamp(38px, 4vw, 58px); line-height: 1.16; letter-spacing: 0; }
.overview-copy h1 { font-size: clamp(38px, 3.6vw, 52px); }
.overview-copy > p { max-width: 640px; margin-bottom: 26px; color: #4f5c6a; font-size: 17px; }
.compatibility { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 30px; padding-top: 17px; border-top: 1px solid #c8d1db; }
.compatibility div { display: grid; }
.compatibility b { color: var(--graphite-deep); }
.compatibility span { color: var(--muted); font-size: 12px; }
.utility-directory { position: relative; min-height: 490px; display: grid; grid-template-columns: 170px 1fr; align-items: center; gap: 24px; }
.directory-list { display: grid; border-top: 1px solid #c6d0da; }
.directory-list span { padding: 15px 5px; color: var(--muted); font-size: 12px; border-bottom: 1px solid #c6d0da; }
.profile-screen { display: flex; align-items: center; justify-content: center; min-height: 470px; padding: 14px; background: #fff; border: 1px solid var(--line); border-radius: 7px; box-shadow: var(--shadow); }
.profile-screen img { width: 248px; max-width: 400px; max-height: 441px; object-fit: contain; border-radius: 5px; }

.module { padding: 82px 0; }
.module-header { display: flex; align-items: baseline; gap: 16px; margin-bottom: 34px; }
.module-header > span { color: var(--alert); font-size: 12px; font-weight: 800; }
.module-header h2 { margin: 0; color: var(--graphite-deep); font-size: clamp(28px, 3vw, 40px); line-height: 1.2; }
.function-matrix { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); }
.function-matrix article { min-height: 240px; padding: 26px 22px; border-right: 1px solid var(--line); }
.function-matrix article:last-child { border-right: 0; }
.function-matrix article > span { color: var(--blue); font-size: 12px; font-weight: 800; }
.function-matrix h3 { margin: 34px 0 12px; color: var(--graphite-deep); font-size: 20px; }
.function-matrix p { margin: 0; color: var(--muted); font-size: 14px; }
.organize-module { background: var(--blue-soft); }
.organize-grid, .question-layout { display: grid; grid-template-columns: 150px 1fr; gap: 46px; }
.module-header-side { display: grid; align-self: start; gap: 8px; margin: 0; }
.organize-table { background: #fff; border: 1px solid var(--line); }
.organize-table > div { display: grid; grid-template-columns: 160px 1fr 1fr; gap: 20px; padding: 17px 20px; border-bottom: 1px solid var(--line); }
.organize-table > div:last-child { border-bottom: 0; }
.organize-table .table-head { color: var(--muted); background: #f7f9fb; font-size: 12px; font-weight: 800; }
.organize-table strong { color: var(--graphite-deep); }
.organize-table span { color: var(--muted); font-size: 14px; }
.organize-note { grid-column: 2; display: grid; grid-template-columns: 180px 1fr 180px; gap: 22px; align-items: center; padding: 20px; background: rgba(255,255,255,.7); border-left: 3px solid var(--alert); }
.organize-note p { margin: 0; color: var(--muted); font-size: 14px; }
.organize-note a, .question-link, .manual-content a, .faq-guide a { color: var(--blue); font-weight: 800; text-decoration: underline; text-underline-offset: 4px; }
.gallery-module { background: #fff; }
.catalog-gallery { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.catalog-gallery figure { margin: 0; border: 1px solid var(--line); border-radius: 6px; overflow: hidden; }
.catalog-gallery figure > div { min-height: 380px; display: flex; align-items: center; justify-content: center; padding: 26px; background: var(--wash); border-bottom: 1px solid var(--line); }
.catalog-gallery img { width: 195px; max-width: 400px; max-height: 347px; object-fit: contain; border-radius: 5px; box-shadow: 0 10px 24px rgba(35,47,61,.1); }
.catalog-gallery figcaption { display: grid; gap: 5px; padding: 19px 21px; }
.catalog-gallery figcaption b { color: var(--graphite-deep); }
.catalog-gallery figcaption span { color: var(--muted); font-size: 14px; }
.advice-module { background: #f7f8fa; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.advice-flow { display: grid; grid-template-columns: repeat(4, 1fr); }
.advice-flow article { position: relative; padding: 24px; border-left: 1px solid var(--line); }
.advice-flow article:first-child { border-left: 0; }
.advice-flow b { color: var(--blue); }
.advice-flow p { margin: 10px 0 0; color: var(--muted); font-size: 14px; }
.short-answers { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.short-answers article { padding: 22px; background: var(--wash); border-top: 2px solid var(--blue); }
.short-answers h3 { color: var(--graphite-deep); font-size: 17px; }
.short-answers p { margin: 0; color: var(--muted); font-size: 14px; }
.question-link { grid-column: 2; }
.final-banner { padding: 46px 0; color: #fff; background: var(--graphite-deep); }
.final-banner-inner { display: flex; align-items: center; justify-content: space-between; gap: 30px; }
.final-banner span { color: #abc1d4; font-size: 13px; }
.final-banner h2 { margin: 5px 0 0; font-size: 30px; }
.control-light { color: var(--graphite-deep); background: #fff; }
.control-outline { color: #fff; border-color: #91a9be; }
.footer { padding: 28px 0; color: var(--muted); background: var(--wash); text-align: center; }
.footer p { margin: 4px 0; font-size: 13px; }

.manual-head, .faq-title { background: var(--wash); border-bottom: 1px solid var(--line); }
.manual-head-rail { min-height: 420px; display: grid; grid-template-columns: 1fr 320px; gap: 80px; align-items: center; padding: 48px 0; }
.manual-head h1, .faq-title h1 { font-size: clamp(36px, 4vw, 52px); }
.manual-head p, .faq-title p { color: var(--muted); font-size: 17px; }
.manual-card { padding: 24px; background: #fff; border: 1px solid var(--line); border-top: 3px solid var(--blue); }
.manual-card b { color: var(--graphite-deep); font-size: 20px; }
.manual-card ol { margin: 16px 0 0; padding-left: 22px; color: var(--muted); }
.manual-layout { display: grid; grid-template-columns: 210px 1fr; gap: 60px; padding-top: 72px; padding-bottom: 88px; }
.manual-menu { position: sticky; top: 100px; align-self: start; display: grid; gap: 11px; padding: 22px; background: var(--blue-soft); }
.manual-menu a { color: var(--muted); font-size: 14px; }
.manual-content > section { padding-bottom: 42px; margin-bottom: 42px; border-bottom: 1px solid var(--line); }
.manual-content > section > span { color: var(--alert); font-size: 12px; font-weight: 800; }
.manual-content h2 { margin: 6px 0 16px; color: var(--graphite-deep); font-size: 28px; }
.manual-content p { color: #4f5d6a; }
.manual-download { display: flex; justify-content: space-between; gap: 24px; align-items: center; padding: 25px; background: var(--wash); border: 1px solid var(--line); }

.faq-title { padding: 70px 0 50px; }
.faq-title p { max-width: 760px; }
.faq-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.faq-tags span { padding: 6px 10px; color: var(--blue); background: #fff; border: 1px solid #b8c9d9; border-radius: 4px; font-size: 12px; font-weight: 800; }
.faq-content { padding: 76px 0 88px; }
.faq-content-rail { display: grid; grid-template-columns: 300px 1fr; gap: 60px; align-items: start; }
.boundary-card { position: sticky; top: 100px; padding: 24px; background: var(--wash); border: 1px solid var(--line); }
.boundary-card h2 { color: var(--graphite-deep); font-size: 24px; }
.boundary-card dl { margin: 0; }
.boundary-card dl > div { padding: 10px 0; border-bottom: 1px solid var(--line); }
.boundary-card dt { color: var(--blue); font-size: 13px; font-weight: 800; }
.boundary-card dd { margin: 2px 0 0; color: var(--muted); font-size: 13px; }
.boundary-card img { width: 145px; max-height: 258px; object-fit: contain; margin: 24px auto 0; border-radius: 5px; box-shadow: var(--shadow); }
.faq-rows details { border-bottom: 1px solid var(--line); }
.faq-rows summary { display: flex; gap: 16px; padding: 19px 0; color: var(--graphite-deep); font-weight: 800; cursor: pointer; list-style: none; }
.faq-rows summary::-webkit-details-marker { display: none; }
.faq-rows summary span { color: var(--alert); font-size: 12px; }
.faq-rows details p { margin: 0; padding: 0 20px 19px 29px; color: var(--muted); }
.faq-guide { margin-top: 34px; display: flex; justify-content: space-between; gap: 20px; padding: 24px; background: var(--blue-soft); border-left: 3px solid var(--alert); }

@media (max-width: 960px) {
  .header-links { display: none; }
  .function-matrix { grid-template-columns: 1fr 1fr; }
  .function-matrix article:nth-child(2) { border-right: 0; }
  .function-matrix article { border-bottom: 1px solid var(--line); }
  .organize-note { grid-template-columns: 150px 1fr; }
  .organize-note a { grid-column: 1 / -1; }
}

@media (max-width: 760px) {
  .header-rail, .overview-grid, .module-rail, .final-banner-inner, .footer-rail, .manual-head-rail, .manual-layout, .faq-title-rail, .faq-content-rail { width: calc(100% - 32px); }
  .header, .header-rail { min-height: 64px; }
  .identity img { width: 38px; height: 38px; }
  .nav-toggle { display: block; margin-left: auto; }
  .navigation { display: none; position: absolute; left: 16px; right: 16px; top: 70px; margin: 0; padding: 9px; background: #fff; border: 1px solid var(--line); border-radius: 6px; box-shadow: var(--shadow); }
  .navigation.open { display: grid; }
  .navigation a { padding: 12px; }
  .overview-grid { min-height: 0; grid-template-columns: 1fr; gap: 14px; padding: 30px 0 22px; }
  h1 { font-size: 33px; }
  .overview-copy > p { font-size: 15px; }
  .overview-actions .control { flex: 1; padding-left: 12px; padding-right: 12px; }
  .compatibility { margin-top: 20px; }
  .compatibility b { font-size: 13px; }
  .utility-directory { min-height: 245px; grid-template-columns: 118px 1fr; gap: 12px; padding-top: 10px; border-top: 1px solid var(--line); }
  .directory-list span { padding: 10px 3px; font-size: 11px; }
  .profile-screen { min-height: 230px; padding: 7px; }
  .profile-screen img { width: 128px; max-height: 228px; }
  .module { padding: 58px 0; }
  .function-matrix { grid-template-columns: 1fr; }
  .function-matrix article { min-height: 0; border-right: 0; }
  .organize-grid, .question-layout { grid-template-columns: 1fr; gap: 28px; }
  .module-header-side { display: flex; }
  .organize-table { overflow-x: auto; }
  .organize-table > div { min-width: 670px; }
  .organize-note { grid-column: 1; grid-template-columns: 1fr; }
  .organize-note a { grid-column: auto; }
  .catalog-gallery { grid-template-columns: 1fr; }
  .catalog-gallery figure > div { min-height: 300px; }
  .catalog-gallery img { width: 165px; max-height: 294px; }
  .advice-flow, .short-answers { grid-template-columns: 1fr; }
  .advice-flow article { border-left: 0; border-bottom: 1px solid var(--line); }
  .question-link { grid-column: 1; }
  .final-banner-inner, .manual-download { align-items: flex-start; flex-direction: column; }
  .final-banner-inner > div:last-child, .manual-download > div { width: 100%; }
  .final-banner .control, .manual-download .control { flex: 1; }
  .manual-head-rail { min-height: 0; grid-template-columns: 1fr; gap: 20px; padding: 40px 0; }
  .manual-head h1 { font-size: 27px; }
  .manual-layout, .faq-content-rail { grid-template-columns: 1fr; gap: 34px; padding-top: 52px; }
  .manual-menu, .boundary-card { position: static; }
  .manual-menu { grid-template-columns: 1fr 1fr; }
  .manual-menu strong { grid-column: 1 / -1; }
  .faq-title { padding: 48px 0 38px; }
  .faq-title h1 { font-size: 31px; }
  .boundary-card img { width: 120px; max-height: 214px; }
  .faq-guide { display: grid; }
}

@media (max-width: 410px) {
  .identity span { font-size: 15px; }
  h1 { font-size: 30px; }
  .utility-directory { grid-template-columns: 112px 1fr; }
}