:root {
  --orange: #f18f21;
  --orange-dark: #c96705;
  --ink: #15212b;
  --muted: #65717b;
  --line: #dfe3e5;
  --soft: #f4f5f4;
  --white: #fff;
  --max: 1240px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; font-family: "Noto Sans SC", "Microsoft YaHei", "PingFang SC", Arial, sans-serif; color: var(--ink); background: var(--white); line-height: 1.6; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
button, select { font: inherit; }
button { color: inherit; }
.skip-link { position: fixed; left: 18px; top: -80px; z-index: 1000; background: var(--ink); color: white; padding: 10px 16px; }
.skip-link:focus { top: 18px; }

.site-header { position: sticky; top: 0; z-index: 50; height: 84px; background: rgba(255,255,255,.97); border-bottom: 1px solid rgba(21,33,43,.1); backdrop-filter: blur(12px); }
.nav-shell { max-width: 1400px; height: 100%; margin: 0 auto; padding: 0 34px; display: flex; align-items: center; gap: 28px; }
.brand { display: flex; align-items: center; gap: 12px; margin-right: auto; min-width: 0; }
.brand img { width: 50px; height: 44px; object-fit: contain; }
.brand span { display: flex; flex-direction: column; min-width: 0; line-height: 1.15; }
.brand strong { font-size: 14px; letter-spacing: .035em; white-space: nowrap; }
.brand small { margin-top: 5px; font-size: 6.5px; color: var(--muted); letter-spacing: .07em; white-space: nowrap; }
.site-nav { display: flex; align-items: center; gap: 22px; font-size: 14px; font-weight: 700; white-space: nowrap; }
.site-nav a { position: relative; padding: 28px 0; }
.site-nav a::after { content: ""; position: absolute; height: 2px; left: 0; right: 100%; bottom: 21px; background: var(--orange); transition: right .25s; }
.site-nav a:hover::after, .site-nav a:focus-visible::after, .site-nav a.active::after { right: 0; }
.language-control > span { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
.language-control select { height: 40px; min-width: 88px; padding: 0 26px 0 10px; border: 1px solid var(--ink); border-radius: 0; background: white; color: var(--ink); font-size: 12px; font-weight: 800; cursor: pointer; direction: ltr; }
.menu-toggle { display: none; border: 0; background: transparent; }

.intro { background: var(--ink); color: white; }
.intro-inner { max-width: var(--max); margin: 0 auto; padding: 76px 34px 68px; }
.eyebrow, .section-index { margin: 0 0 18px; color: var(--orange); font-size: 12px; font-weight: 900; letter-spacing: .18em; }
.intro h1 { margin: 0; font-size: clamp(42px, 6vw, 74px); line-height: 1.06; letter-spacing: -.05em; }
.intro-copy { max-width: 760px; margin: 24px 0 0; color: #b9c3ca; font-size: 18px; line-height: 1.9; }
.viewer-note { max-width: 760px; margin-top: 32px; padding-top: 22px; border-top: 1px solid rgba(255,255,255,.18); display: flex; align-items: center; gap: 16px; }
.viewer-note > span { flex: 0 0 auto; display: grid; place-items: center; width: 58px; height: 40px; border: 1px solid var(--orange); color: var(--orange); font-weight: 900; }
.viewer-note p { margin: 0; color: #dce2e6; }

.manuals, .viewer-section { max-width: var(--max); margin: 0 auto; padding: 72px 34px; }
.section-heading, .viewer-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 30px; margin-bottom: 34px; }
.section-heading h2, .viewer-heading h2 { margin: 0; font-size: clamp(30px, 4vw, 48px); line-height: 1.08; letter-spacing: -.04em; }
.section-heading > p { max-width: 460px; margin: 0; color: var(--muted); text-align: right; }
.manual-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); border-top: 1px solid var(--line); border-left: 1px solid var(--line); }
.manual-card { min-height: 250px; display: grid; grid-template-columns: 150px 1fr; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); background: white; transition: transform .25s, box-shadow .25s; }
.manual-card:hover { position: relative; z-index: 2; transform: translateY(-4px); box-shadow: 0 20px 40px rgba(21,33,43,.09); }
.document-mark { display: flex; flex-direction: column; justify-content: space-between; padding: 26px 22px; background: var(--soft); border-right: 1px solid var(--line); overflow: hidden; }
.document-mark::before { content: ""; width: 44px; height: 56px; border: 2px solid var(--orange); box-shadow: 8px 8px 0 rgba(241,143,33,.16); }
.document-mark span { color: var(--orange-dark); font-size: 11px; font-weight: 900; letter-spacing: .18em; }
.document-mark strong { font-size: 22px; line-height: 1; overflow-wrap: anywhere; }
.manual-body { padding: 27px 28px 24px; display: flex; flex-direction: column; }
.manual-type { margin: 0; color: var(--muted); font-size: 12px; letter-spacing: .12em; }
.manual-body h3 { margin: 6px 0 8px; font-size: 32px; line-height: 1; }
.manual-meta { display: flex; gap: 15px; margin: 0; color: var(--muted); font-size: 13px; }
.manual-meta span + span::before { content: "·"; margin-right: 15px; }
.manual-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: auto; padding-top: 24px; }
.view-button, .download-button, .button { min-height: 44px; display: inline-flex; align-items: center; justify-content: center; padding: 0 18px; border: 1px solid var(--ink); background: transparent; font-size: 13px; font-weight: 800; cursor: pointer; transition: background .2s, color .2s, transform .2s; }
.view-button { background: var(--orange); border-color: var(--orange); }
.view-button:hover, .download-button:hover, .button:hover { transform: translateY(-2px); }
.download-button:hover, .button-ghost:hover { background: var(--ink); color: white; }

.viewer-section { padding-top: 24px; }
.viewer-section[hidden] { display: none; }
.viewer-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.button-primary { background: var(--orange); border-color: var(--orange); }
.native-tip { margin: -12px 0 18px; color: var(--muted); font-size: 14px; }
.pdf-frame-wrap { height: min(78vh, 920px); min-height: 620px; background: #e9ecee; border: 1px solid var(--line); }
#pdf-frame { width: 100%; height: 100%; border: 0; background: #e9ecee; }

.site-footer { padding: 34px max(34px, calc((100vw - var(--max)) / 2 + 34px)); display: flex; justify-content: space-between; gap: 30px; background: var(--ink); color: white; }
.site-footer > div:first-child { display: flex; flex-direction: column; }
.site-footer span { color: #9ca8b0; font-size: 11px; }
.footer-links { display: flex; align-items: center; gap: 24px; font-size: 13px; }
.footer-links a:hover { color: var(--orange); }

[dir="rtl"] .brand { margin-right: 0; margin-left: auto; }
[dir="rtl"] .section-heading > p { text-align: left; }
[dir="rtl"] .document-mark { border-right: 0; border-left: 1px solid var(--line); }
[dir="rtl"] .site-nav a::after { left: 100%; right: 0; }
[dir="rtl"] .site-nav a:hover::after, [dir="rtl"] .site-nav a.active::after { left: 0; }

@media (max-width: 1180px) {
  .site-nav { gap: 15px; font-size: 13px; }
  .brand strong { max-width: 230px; overflow: hidden; text-overflow: ellipsis; }
}

@media (max-width: 920px) {
  .site-header { height: 70px; }
  .nav-shell { padding: 0 20px; }
  .brand img { width: 43px; height: 39px; }
  .brand strong { font-size: 12px; max-width: none; }
  .brand small { display: none; }
  .menu-toggle { order: 3; width: 42px; height: 42px; padding: 9px; display: grid; align-content: center; gap: 5px; }
  .menu-toggle span { width: 100%; height: 2px; background: var(--ink); }
  .menu-toggle em { position: absolute; width: 1px; height: 1px; overflow: hidden; }
  .language-control { margin-left: auto; }
  .language-control select { min-width: 75px; width: 75px; }
  .site-nav { position: fixed; top: 70px; left: 0; right: 0; display: grid; gap: 0; padding: 12px 20px 20px; background: white; border-bottom: 1px solid var(--line); transform: translateY(-140%); opacity: 0; visibility: hidden; transition: .3s; }
  .site-nav.open { transform: none; opacity: 1; visibility: visible; }
  .site-nav a { padding: 13px 0; border-bottom: 1px solid var(--line); }
  .site-nav a::after { display: none; }
  .manual-grid { grid-template-columns: 1fr; }
}

@media (max-width: 620px) {
  .brand strong { max-width: 178px; font-size: 11px; line-height: 1.25; white-space: normal; }
  .language-control select { min-width: 68px; width: 68px; padding-left: 6px; padding-right: 16px; }
  .intro-inner { padding: 58px 20px 50px; }
  .intro h1 { font-size: 42px; }
  .intro-copy { font-size: 16px; }
  .viewer-note { align-items: flex-start; }
  .manuals, .viewer-section { padding: 52px 20px; }
  .section-heading, .viewer-heading { align-items: flex-start; flex-direction: column; }
  .section-heading > p { text-align: left; }
  .manual-card { min-height: 0; grid-template-columns: 92px 1fr; }
  .document-mark { padding: 22px 14px; }
  .document-mark::before { width: 32px; height: 42px; }
  .document-mark strong { font-size: 15px; }
  .manual-body { padding: 22px 18px; }
  .manual-body h3 { font-size: 27px; }
  .manual-actions { flex-direction: column; }
  .view-button, .download-button { width: 100%; }
  .pdf-frame-wrap { min-height: 70vh; height: 70vh; }
  .site-footer { padding: 30px 20px; flex-direction: column; }
  .footer-links { align-items: flex-start; flex-direction: column; gap: 8px; }
}