/* ============================================================
   Aolong Chemical — Trust & Authority design system
   Palette: navy #0F172A · CTA blue #0369A1 · bg #F8FAFC
   Type:    IBM Plex Sans (400/500/600/700)
   ============================================================ */

:root {
  --primary: #0F172A;
  --primary-2: #1E293B;
  --secondary: #334155;
  --accent: #0369A1;
  --accent-strong: #075985;
  --accent-soft: #E0F2FE;
  --bg: #F8FAFC;
  --surface: #FFFFFF;
  --fg: #020617;
  --fg-soft: #475569;
  --muted: #E8ECF1;
  --border: #E2E8F0;
  --destructive: #DC2626;
  --ring: #0369A1;

  --font: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI',
          'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;

  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 16px;

  --shadow-sm: 0 1px 2px rgba(15, 23, 42, .06);
  --shadow: 0 4px 16px rgba(15, 23, 42, .08);
  --shadow-lg: 0 16px 40px rgba(15, 23, 42, .14);

  --space-1: 4px; --space-2: 8px; --space-3: 12px; --space-4: 16px;
  --space-5: 24px; --space-6: 32px; --space-7: 48px; --space-8: 64px;
  --space-9: 96px;

  --header-h: 72px;
  --container: 1200px;
  --ease: cubic-bezier(.2, .7, .3, 1);
}

/* ------------------------------- base ------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}
body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.65;
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img { max-width: 100%; height: auto; display: block; }
h1, h2, h3, h4 { color: var(--primary); line-height: 1.25; margin: 0 0 var(--space-4); font-weight: 700; letter-spacing: -.01em; }
h1 { font-size: clamp(1.9rem, 1.2rem + 2.4vw, 3rem); }
h2 { font-size: clamp(1.4rem, 1.1rem + 1.2vw, 2rem); }
h3 { font-size: 1.125rem; }
p { margin: 0 0 var(--space-4); }
a { color: var(--accent); text-decoration: none; transition: color .18s var(--ease); }
a:hover { color: var(--accent-strong); }
ul, ol { margin: 0; padding: 0; list-style: none; }
:focus-visible { outline: 3px solid var(--ring); outline-offset: 2px; border-radius: 4px; }
::selection { background: #BAE6FD; }

.container { max-width: var(--container); margin-inline: auto; padding-inline: var(--space-5); }
.container-narrow { max-width: 860px; }

.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 2000;
  background: var(--primary); color: #fff; padding: var(--space-3) var(--space-4);
  border-radius: 0 0 var(--radius-sm) 0;
}
.skip-link:focus { left: 0; color: #fff; }

.ico { width: 1.05em; height: 1.05em; flex: none; vertical-align: -.18em; }

/* ------------------------------ buttons ----------------------------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2);
  font: inherit; font-weight: 600; font-size: 1rem; line-height: 1;
  padding: 14px 24px; min-height: 48px;
  border-radius: var(--radius-sm); border: 2px solid transparent;
  cursor: pointer; text-align: center; white-space: nowrap;
  transition: background .18s var(--ease), color .18s var(--ease), border-color .18s var(--ease), transform .18s var(--ease), box-shadow .18s var(--ease);
}
.btn:active { transform: scale(.98); }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-strong); color: #fff; box-shadow: var(--shadow); }
.btn-ghost { background: rgba(255,255,255,.08); color: #fff; border-color: rgba(255,255,255,.55); backdrop-filter: blur(4px); }
.btn-ghost:hover { background: rgba(255,255,255,.18); color: #fff; }
.btn-light { background: #fff; color: var(--accent-strong); }
.btn-light:hover { background: var(--accent-soft); color: var(--accent-strong); }
.btn-outline { background: transparent; color: var(--accent-strong); border-color: var(--border); }
.btn-outline:hover { border-color: var(--accent); background: var(--accent-soft); color: var(--accent-strong); }
.btn-sm { padding: 10px 16px; min-height: 40px; font-size: .9rem; }
.btn-lg { padding: 16px 30px; min-height: 54px; font-size: 1.05rem; }
.btn-block { width: 100%; }

.text-link { display: inline-flex; align-items: center; gap: 6px; font-weight: 600; }
.text-link .ico { transition: transform .18s var(--ease); }
.text-link:hover .ico { transform: translateX(4px); }

/* ------------------------------ topbar ------------------------------ */
.topbar { background: var(--primary); color: #CBD5E1; font-size: .82rem; }
.topbar-inner { display: flex; align-items: center; justify-content: space-between; gap: var(--space-4); min-height: 38px; }
.topbar p { margin: 0; }
.topbar-welcome { opacity: .85; }
.topbar-contact { display: flex; gap: var(--space-5); }
.topbar-contact a { display: inline-flex; align-items: center; gap: 6px; color: #E2E8F0; }
.topbar-contact a:hover { color: #7DD3FC; }
@media (max-width: 720px) { .topbar-welcome { display: none; } .topbar-inner { justify-content: center; } }

/* ------------------------------ header ------------------------------ */
.site-header {
  position: sticky; top: 0; z-index: 1000;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  transition: box-shadow .2s var(--ease);
}
.site-header.is-scrolled { box-shadow: var(--shadow); }
.header-inner { display: flex; align-items: center; gap: var(--space-5); min-height: var(--header-h); }

.logo { display: inline-flex; align-items: center; gap: 10px; color: var(--primary); font-weight: 700; font-size: 1.15rem; letter-spacing: -.01em; }
.logo:hover { color: var(--accent); }
.logo-mark { width: 38px; height: 38px; }
.logo-text span { font-weight: 400; color: var(--secondary); }

.main-nav { margin-left: auto; }
.nav-list { display: flex; gap: var(--space-1); }
.nav-item > a {
  display: inline-flex; align-items: center; gap: 4px;
  padding: 12px 14px; font-weight: 500; color: var(--primary); border-radius: var(--radius-sm);
  position: relative;
}
.nav-item > a .ico { opacity: .6; transition: transform .18s var(--ease); }
.nav-item > a:hover { color: var(--accent); background: var(--accent-soft); }
.nav-item.is-active > a { color: var(--accent-strong); }
.nav-item.is-active > a::after {
  content: ""; position: absolute; left: 14px; right: 14px; bottom: 4px; height: 2px;
  background: var(--accent); border-radius: 2px;
}
.nav-item.has-mega { position: relative; }
.nav-item.has-mega:hover > a .ico, .nav-item.has-mega:focus-within > a .ico { transform: rotate(180deg); }

.mega {
  position: absolute; top: 100%; left: 50%; transform: translateX(-50%) translateY(8px);
  width: min(680px, calc(100vw - 48px));
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg); padding: var(--space-4);
  opacity: 0; visibility: hidden; pointer-events: none;
  transition: opacity .18s var(--ease), transform .18s var(--ease), visibility .18s;
}
.nav-item.has-mega:hover .mega, .nav-item.has-mega:focus-within .mega {
  opacity: 1; visibility: visible; pointer-events: auto; transform: translateX(-50%) translateY(0);
}
.mega-grid ul { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-2); }
.mega-link { display: block; padding: var(--space-3) var(--space-4); border-radius: var(--radius); transition: background .15s var(--ease); }
.mega-link:hover { background: var(--accent-soft); }
.mega-name { display: block; font-weight: 600; color: var(--primary); }
.mega-desc { display: block; font-size: .82rem; color: var(--fg-soft); margin-top: 2px; }

.header-actions { display: flex; align-items: center; gap: var(--space-3); }
.lang-switch {
  display: inline-flex; align-items: center; gap: 6px;
  font-weight: 600; font-size: .9rem; color: var(--secondary);
  padding: 9px 12px; border: 1px solid var(--border); border-radius: var(--radius-sm); min-height: 40px;
}
.lang-switch:hover { border-color: var(--accent); color: var(--accent); background: var(--accent-soft); }
.nav-toggle {
  display: none; background: none; border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 8px 10px; cursor: pointer; color: var(--primary); min-width: 44px; min-height: 44px;
}
.nav-toggle .ico { width: 22px; height: 22px; }

.mobile-nav { display: none; border-top: 1px solid var(--border); background: var(--surface); }
.mobile-nav.is-open { display: block; }
.mobile-nav a { display: block; padding: 14px var(--space-5); font-weight: 500; color: var(--primary); border-bottom: 1px solid var(--muted); }
.mobile-nav a.is-active { color: var(--accent-strong); background: var(--accent-soft); }

@media (max-width: 1080px) {
  .main-nav, .header-cta { display: none; }
  .nav-toggle { display: inline-flex; align-items: center; justify-content: center; }
  .header-inner { justify-content: space-between; }
  .main-nav + .header-actions { margin-left: auto; }
}

/* ------------------------------- hero ------------------------------- */
.hero { position: relative; color: #fff; overflow: hidden; background: var(--primary); }
.hero-bg, .page-hero-about .hero-bg { position: absolute; inset: 0; }
.hero-bg img { width: 100%; height: 100%; object-fit: cover; opacity: .55; }
.hero::after {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(100deg, rgba(2,6,23,.92) 18%, rgba(2,6,23,.55) 55%, rgba(3,105,161,.25));
}
.hero-inner { position: relative; z-index: 1; padding-block: var(--space-9) calc(var(--space-9) + var(--space-4)); max-width: 780px; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: .85rem; font-weight: 600; letter-spacing: .02em;
  background: rgba(125,211,252,.14); border: 1px solid rgba(125,211,252,.4);
  color: #BAE6FD; padding: 8px 14px; border-radius: 999px; margin-bottom: var(--space-5);
}
.hero h1 { color: #fff; margin-bottom: var(--space-4); }
.hero-sub { font-size: clamp(1rem, .95rem + .4vw, 1.2rem); color: #CBD5E1; max-width: 620px; margin-bottom: var(--space-6); }
.hero-cta { display: flex; gap: var(--space-3); flex-wrap: wrap; }

/* stats */
.stats-band { background: var(--primary); color: #fff; border-top: 1px solid rgba(148,163,184,.15); }
.stats-inner { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-4); padding-block: var(--space-6); }
.stat { text-align: center; }
.stat strong { display: block; font-size: clamp(1.6rem, 1.2rem + 1.4vw, 2.4rem); color: #7DD3FC; font-weight: 700; }
.stat span { font-size: .88rem; color: #CBD5E1; }

/* ----------------------------- sections ----------------------------- */
.section { padding-block: var(--space-8); }
.section-alt { background: var(--surface); border-block: 1px solid var(--border); }
.section-head { max-width: 720px; margin-bottom: var(--space-6); }
.section-head p { color: var(--fg-soft); font-size: 1.05rem; margin: 0; }
.section-head-row { display: flex; align-items: flex-end; justify-content: space-between; gap: var(--space-4); max-width: none; }

/* ----------------------------- category ----------------------------- */
.cat-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: var(--space-5); }
.cat-card {
  display: flex; flex-direction: column; background: var(--surface);
  border: 1px solid var(--border); border-radius: var(--radius-lg); overflow: hidden;
  color: inherit; box-shadow: var(--shadow-sm);
  transition: transform .2s var(--ease), box-shadow .2s var(--ease), border-color .2s var(--ease);
}
.cat-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: #BAE6FD; color: inherit; }
.cat-media { aspect-ratio: 4 / 3; overflow: hidden; background: var(--muted); }
.cat-media img { width: 100%; height: 100%; object-fit: cover; transition: transform .35s var(--ease); }
.cat-card:hover .cat-media img { transform: scale(1.045); }
.cat-body { padding: var(--space-5); display: flex; flex-direction: column; gap: var(--space-2); flex: 1; }
.cat-body h3 { margin: 0; }
.cat-body p { margin: 0; color: var(--fg-soft); font-size: .95rem; flex: 1; }

/* why cards */
.why-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: var(--space-5); }
.why-card {
  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: var(--space-5);
}
.why-icon {
  width: 48px; height: 48px; display: grid; place-items: center;
  background: var(--accent-soft); color: var(--accent-strong);
  border-radius: var(--radius); margin-bottom: var(--space-4);
}
.why-icon .ico { width: 24px; height: 24px; }
.why-card h3 { margin-bottom: var(--space-2); }
.why-card p { margin: 0; color: var(--fg-soft); font-size: .95rem; }

/* app chips */
.app-chip-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: var(--space-4); }
.app-chip {
  position: relative; border-radius: var(--radius-lg); overflow: hidden; aspect-ratio: 16 / 10;
  color: #fff; display: flex; align-items: flex-end; box-shadow: var(--shadow-sm);
}
.app-chip img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; transition: transform .35s var(--ease); }
.app-chip::after { content: ""; position: absolute; inset: 0; background: linear-gradient(180deg, transparent 35%, rgba(2,6,23,.85)); }
.app-chip span { position: relative; z-index: 1; padding: var(--space-4); font-weight: 600; }
.app-chip:hover img { transform: scale(1.05); }
.app-chip:hover { color: #fff; }

/* ------------------------------- cards ------------------------------ */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: var(--space-5); }
.card-grid-3 { grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.card-grid-4 { grid-template-columns: repeat(auto-fill, minmax(210px, 1fr)); }
.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg);
  overflow: hidden; display: flex; flex-direction: column; box-shadow: var(--shadow-sm);
  transition: transform .2s var(--ease), box-shadow .2s var(--ease), border-color .2s var(--ease);
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: #BAE6FD; }
.card-media { display: block; aspect-ratio: 1; overflow: hidden; background: var(--muted); }
.news-card .card-media { aspect-ratio: 16 / 9; }
.card-media img { width: 100%; height: 100%; object-fit: cover; transition: transform .35s var(--ease); }
.card:hover .card-media img { transform: scale(1.05); }
.card-body { padding: var(--space-4) var(--space-5) var(--space-5); display: flex; flex-direction: column; gap: var(--space-2); flex: 1; }
.card-cat { margin: 0; font-size: .78rem; font-weight: 600; letter-spacing: .06em; text-transform: uppercase; color: var(--accent); }
.card-title { margin: 0; font-size: 1.08rem; }
.card-title a { color: var(--primary); }
.card-title a:hover { color: var(--accent); }
.card-sub { margin: 0; font-size: .88rem; color: var(--fg-soft); flex: 1; }
.card-meta { margin: auto 0 0; padding-top: var(--space-3); border-top: 1px dashed var(--border); font-size: .85rem; color: var(--secondary); font-variant-numeric: tabular-nums; }
.card-meta span { color: var(--fg-soft); font-weight: 600; margin-right: 4px; }

.card-tags { display: flex; align-items: center; gap: var(--space-3); margin: 0; font-size: .82rem; color: var(--fg-soft); flex-wrap: wrap; }
.tag { display: inline-block; font-size: .74rem; font-weight: 600; letter-spacing: .04em; text-transform: uppercase; padding: 4px 10px; border-radius: 999px; background: var(--muted); color: var(--secondary); }
.tag-company { background: #DCFCE7; color: #166534; }
.tag-industry { background: var(--accent-soft); color: var(--accent-strong); }
.tag-technical { background: #FEF3C7; color: #92400E; }

/* ---------------------------- page hero ----------------------------- */
.page-hero {
  background: linear-gradient(120deg, var(--primary) 0%, #16294d 60%, #0b3a56);
  color: #E2E8F0; padding: var(--space-7) 0 var(--space-7);
}
.page-hero h1 { color: #fff; margin-bottom: var(--space-3); }
.page-hero > .container > p { max-width: 760px; color: #CBD5E1; font-size: 1.05rem; }
.page-hero-cat, .page-hero-about { position: relative; overflow: hidden; }
.page-hero-about .hero-bg img { opacity: .35; }
.page-hero-about::after { content: ""; position: absolute; inset: 0; background: linear-gradient(100deg, rgba(2,6,23,.9) 20%, rgba(2,6,23,.55)); }
.page-hero-about .container { position: relative; z-index: 1; }

.breadcrumb { margin-bottom: var(--space-4); font-size: .85rem; }
.breadcrumb ol { display: flex; flex-wrap: wrap; gap: 6px; }
.breadcrumb li { display: flex; align-items: center; gap: 6px; color: #64748B; }
.breadcrumb li + li::before { content: "/"; color: #94A3B8; }
.breadcrumb a { color: var(--accent-strong); font-weight: 500; }
.breadcrumb a:hover { color: var(--accent); text-decoration: underline; }
.breadcrumb [aria-current="page"] { color: var(--primary); font-weight: 600; }

/* light-on-dark breadcrumbs inside hero areas */
.page-hero .breadcrumb li, .page-hero-about .breadcrumb li { color: #94A3B8; }
.page-hero .breadcrumb li + li::before, .page-hero-about .breadcrumb li + li::before { color: #64748B; }
.page-hero .breadcrumb a, .page-hero-about .breadcrumb a { color: #BAE6FD; }
.page-hero .breadcrumb a:hover, .page-hero-about .breadcrumb a:hover { color: #fff; }
.page-hero .breadcrumb [aria-current="page"], .page-hero-about .breadcrumb [aria-current="page"] { color: #E2E8F0; }

/* products index filters */
.filter-row { display: flex; flex-wrap: wrap; gap: var(--space-2); margin-top: var(--space-5); }
.filter-chip {
  background: rgba(255,255,255,.1); border: 1px solid rgba(203,213,225,.35); color: #E2E8F0;
  padding: 9px 16px; border-radius: 999px; font-size: .88rem; font-weight: 500;
}
.filter-chip:hover { background: rgba(125,211,252,.2); border-color: #7DD3FC; color: #fff; }

.product-family { padding-block: var(--space-7); border-bottom: 1px solid var(--border); }
.product-family:last-of-type { border-bottom: 0; }
.family-head { display: flex; align-items: flex-end; justify-content: space-between; gap: var(--space-4); margin-bottom: var(--space-5); flex-wrap: wrap; }
.family-head p { margin: 0; color: var(--fg-soft); }
.family-head h2 a { color: var(--primary); }
.family-head h2 a:hover { color: var(--accent); }

/* -------------------------- product listing ------------------------- */
.page-body { padding-block: var(--space-7); }
.page-body-layout { display: grid; grid-template-columns: 260px 1fr; gap: var(--space-7); align-items: start; }
.side-nav { position: sticky; top: calc(var(--header-h) + 16px); display: flex; flex-direction: column; gap: var(--space-5); }
.side-nav h2 { font-size: .95rem; text-transform: uppercase; letter-spacing: .06em; color: var(--fg-soft); }
.side-nav ul { display: flex; flex-direction: column; gap: 4px; }
.side-nav ul a {
  display: flex; justify-content: space-between; align-items: center; gap: var(--space-3);
  padding: 10px 14px; border-radius: var(--radius-sm); color: var(--primary); font-weight: 500;
  border: 1px solid transparent;
}
.side-nav a span { font-size: .78rem; color: var(--fg-soft); background: var(--muted); border-radius: 999px; padding: 2px 9px; }
.side-nav a:hover { background: var(--accent-soft); color: var(--accent-strong); }
.side-nav a.is-active { background: var(--accent); color: #fff; }
.side-nav a.is-active span { background: rgba(255,255,255,.2); color: #fff; }
.side-cta { background: var(--primary); color: #CBD5E1; border-radius: var(--radius-lg); padding: var(--space-5); }
.side-cta p { font-size: .95rem; margin-bottom: var(--space-4); }
.products-count { color: var(--fg-soft); font-size: .9rem; margin-bottom: var(--space-4); font-variant-numeric: tabular-nums; }
.family-intro { margin-top: var(--space-7); padding-top: var(--space-6); border-top: 1px solid var(--border); max-width: 800px; }
.family-intro p { color: var(--fg-soft); }

/* --------------------------- product detail ------------------------- */
.product-layout { display: grid; grid-template-columns: minmax(300px, 420px) 1fr; gap: var(--space-7); align-items: start; }
.product-figure {
  margin: 0 0 var(--space-4); border: 1px solid var(--border); border-radius: var(--radius-lg);
  overflow: hidden; background: var(--surface); box-shadow: var(--shadow-sm);
}
.quick-specs { display: flex; flex-direction: column; gap: var(--space-2); margin-bottom: var(--space-4); }
.quick-spec {
  display: flex; justify-content: space-between; align-items: center; gap: var(--space-3);
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 10px 14px; font-size: .92rem;
}
.quick-spec span { color: var(--fg-soft); }
.quick-spec strong { color: var(--primary); font-variant-numeric: tabular-nums; }
.product-media-col .btn { margin-bottom: var(--space-2); }
.product-main .card-cat { margin-bottom: var(--space-2); }
.product-main h1 { margin-bottom: var(--space-1); }
.product-chem { color: var(--fg-soft); font-size: 1.02rem; margin-bottom: var(--space-3); }
.product-summary {
  font-size: 1.08rem; color: var(--primary); border-left: 3px solid var(--accent);
  background: var(--accent-soft); padding: var(--space-4); border-radius: 0 var(--radius) var(--radius) 0;
  margin-bottom: var(--space-6);
}
.product-section { margin-bottom: var(--space-6); }
.product-section h2 { font-size: 1.2rem; padding-bottom: var(--space-2); border-bottom: 2px solid var(--border); margin-bottom: var(--space-4); }
.product-cols { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-6); }
.check-list li { display: flex; gap: 10px; align-items: flex-start; margin-bottom: var(--space-2); }
.check-list .ico { color: var(--accent); margin-top: 5px; }
.dot-list li { position: relative; padding-left: 20px; margin-bottom: var(--space-2); color: var(--secondary); }
.dot-list li::before { content: ""; position: absolute; left: 2px; top: .62em; width: 7px; height: 7px; border-radius: 50%; background: var(--accent); }

.table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius); }
.spec-layout { display: grid; grid-template-columns: 1fr; gap: var(--space-5); align-items: start; }
.spec-layout.has-structure { grid-template-columns: minmax(280px, 460px) 1fr; }
.spec-section { margin-top: var(--space-6); padding-top: var(--space-6); border-top: 1px solid var(--border); }
.spec-section .table-wrap { height: 100%; }
.spec-section .spec-table { height: 100%; }
.structure-figure {
  margin: 0; background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-sm);
  display: flex; flex-direction: column; height: 100%;
}
.structure-figure img {
  width: 100%; height: auto; aspect-ratio: 4 / 3; object-fit: contain;
  background: #fff; padding: var(--space-4);
}
.structure-figure figcaption {
  display: flex; justify-content: space-between; align-items: center; gap: var(--space-3);
  padding: 10px 14px; border-top: 1px solid var(--muted);
  font-size: .82rem; font-weight: 600; color: var(--fg-soft);
  text-transform: uppercase; letter-spacing: .05em;
}
.structure-figure .structure-formula {
  font-family: ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
  font-weight: 600; color: var(--accent-strong); text-transform: none; letter-spacing: 0;
  font-size: .95rem;
}
@media (max-width: 900px) {
  .spec-layout.has-structure { grid-template-columns: 1fr; }
  .structure-figure { max-width: 420px; }
}
.spec-table { width: 100%; border-collapse: collapse; font-size: .95rem; background: var(--surface); }
.spec-table th, .spec-table td { padding: 12px 18px; text-align: left; border-bottom: 1px solid var(--muted); }
.spec-table tr:last-child th, .spec-table tr:last-child td { border-bottom: 0; }
.spec-table th { width: 38%; color: var(--fg-soft); font-weight: 500; background: var(--bg); }
.spec-table td { color: var(--primary); font-weight: 500; font-variant-numeric: tabular-nums; }

.product-related { margin-top: var(--space-8); padding-top: var(--space-6); border-top: 1px solid var(--border); }
.product-related h2 { margin-bottom: var(--space-5); }

/* ---------------------------- applications -------------------------- */
.app-list { display: flex; flex-direction: column; gap: var(--space-7); }
.app-section {
  display: grid; grid-template-columns: minmax(280px, 480px) 1fr; gap: var(--space-6);
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg);
  overflow: hidden; box-shadow: var(--shadow-sm);
}
.app-media { min-height: 260px; }
.app-media img { width: 100%; height: 100%; object-fit: cover; }
.app-body { padding: var(--space-6) var(--space-6) var(--space-6) 0; }
.app-summary { font-weight: 600; color: var(--primary); }
.app-body > p:not(.app-summary) { color: var(--fg-soft); }
.app-body h3 { font-size: .95rem; text-transform: uppercase; letter-spacing: .05em; color: var(--fg-soft); margin-top: var(--space-5); }
.app-links { display: flex; flex-wrap: wrap; gap: var(--space-2); }
.pill-link {
  border: 1px solid var(--border); border-radius: 999px; padding: 8px 16px;
  font-size: .88rem; font-weight: 500; color: var(--primary); background: var(--bg);
}
.pill-link:hover { border-color: var(--accent); background: var(--accent-soft); color: var(--accent-strong); }

/* ------------------------------- news ------------------------------- */
.news-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: var(--space-5); }
.news-grid-2 { grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); }

.article-page { max-width: 820px; }
.article-head .card-tags { margin-bottom: var(--space-3); }
.article-head h1 { margin-bottom: var(--space-5); }
.article-figure { margin: 0 0 var(--space-6); border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow-sm); }
.article-body { font-size: 1.06rem; }
.article-body p { margin-bottom: var(--space-5); color: var(--secondary); }
.article-body p:first-child::first-letter {
  float: left; font-size: 3.2em; line-height: .9; padding-right: 10px; padding-top: 4px;
  font-weight: 700; color: var(--accent);
}
.article-body h2 {
  font-size: 1.35rem; line-height: 1.3; color: var(--primary);
  margin: var(--space-7) 0 var(--space-4);
}
.article-body h3 {
  font-size: 1.12rem; line-height: 1.35; color: var(--primary-2);
  margin: var(--space-6) 0 var(--space-3);
}
.article-body ul, .article-body ol {
  margin: 0 0 var(--space-5); padding-left: 1.4rem; color: var(--secondary);
}
.article-body li { margin-bottom: var(--space-2); }
.article-body li::marker { color: var(--accent); font-weight: 600; }
.article-body strong { color: var(--primary); font-weight: 600; }
.article-body a {
  color: var(--accent); text-decoration: underline;
  text-decoration-color: rgba(3, 105, 161, .35); text-underline-offset: 3px;
}
.article-body a:hover { color: var(--accent-strong); text-decoration-color: currentColor; }
.article-body blockquote {
  margin: 0 0 var(--space-5); padding: var(--space-4) var(--space-5);
  border-left: 3px solid var(--accent); background: var(--accent-soft);
  border-radius: 0 var(--radius) var(--radius) 0; color: var(--primary-2);
}
.article-body blockquote p { margin: 0; color: var(--primary-2); }
.article-body > *:last-child { margin-bottom: 0; }
.article-foot { margin-top: var(--space-6); padding-top: var(--space-5); border-top: 1px solid var(--border); }
.article-related { margin-top: var(--space-7); }
.article-related h2 { font-size: 1.2rem; }
.related-list li { padding: var(--space-3) 0; border-bottom: 1px solid var(--muted); }
.related-list a { display: block; font-weight: 600; color: var(--primary); margin-bottom: 2px; }
.related-list a:hover { color: var(--accent); }
.related-list time { font-size: .82rem; color: var(--fg-soft); }

/* ------------------------------- about ------------------------------ */
.about-mission { display: grid; grid-template-columns: 1.2fr .8fr; gap: var(--space-7); align-items: center; }
.about-mission p { font-size: 1.08rem; color: var(--secondary); }
.about-figure { margin: 0; border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow); }
.cert-row { display: flex; flex-wrap: wrap; gap: var(--space-2); margin-top: var(--space-4); }
.cert-chip {
  display: inline-flex; align-items: center; gap: 7px;
  background: var(--surface); border: 1px solid var(--border); color: var(--secondary);
  font-size: .84rem; font-weight: 600; padding: 8px 14px; border-radius: 999px;
}
.cert-chip .ico { color: var(--accent); }

.timeline { position: relative; padding-left: 26px; }
.timeline::before { content: ""; position: absolute; left: 7px; top: 8px; bottom: 8px; width: 2px; background: linear-gradient(var(--accent), #BAE6FD); }
.timeline-item { position: relative; padding-bottom: var(--space-5); }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-item::before {
  content: ""; position: absolute; left: -26px; top: 7px; width: 16px; height: 16px;
  border-radius: 50%; background: #fff; border: 3px solid var(--accent);
}
.timeline-year { font-weight: 700; color: var(--accent-strong); margin-right: var(--space-2); }
.timeline-item p { display: inline; color: var(--secondary); margin: 0; }

.about-factory { display: grid; grid-template-columns: 1.4fr .6fr; gap: var(--space-6); align-items: center; }
.about-factory-text p { color: var(--secondary); }
.about-factory-imgs img { border-radius: var(--radius-lg); box-shadow: var(--shadow); }

/* ------------------------------ contact ----------------------------- */
.contact-layout { display: grid; grid-template-columns: 1.25fr .75fr; gap: var(--space-7); align-items: start; }
.contact-form-col h2, .contact-info-col h2 { font-size: 1.35rem; }
.form-note { color: var(--fg-soft); font-size: .9rem; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-4); }
.form-field { margin-bottom: var(--space-4); }
.form-field label { display: block; font-weight: 600; font-size: .92rem; margin-bottom: 6px; color: var(--primary); }
.form-field input, .form-field select, .form-field textarea {
  width: 100%; font: inherit; color: var(--fg);
  background: var(--surface); border: 1.5px solid var(--border); border-radius: var(--radius-sm);
  padding: 12px 14px; min-height: 48px; transition: border-color .15s var(--ease), box-shadow .15s var(--ease);
}
.form-field textarea { resize: vertical; min-height: 140px; }
.form-field input:focus, .form-field select:focus, .form-field textarea:focus {
  outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(3,105,161,.15);
}
.form-field .is-invalid, .form-field input[aria-invalid="true"], .form-field textarea[aria-invalid="true"] {
  border-color: var(--destructive);
}
.form-success { margin-top: var(--space-4); background: #DCFCE7; color: #166534; border: 1px solid #86EFAC; border-radius: var(--radius-sm); padding: var(--space-3) var(--space-4); font-weight: 500; }
.form-error { margin-top: var(--space-4); background: #FEE2E2; color: #991B1B; border: 1px solid #FCA5A5; border-radius: var(--radius-sm); padding: var(--space-3) var(--space-4); font-weight: 500; }
.contact-info-col { background: var(--primary); color: #CBD5E1; border-radius: var(--radius-lg); padding: var(--space-6); }
.contact-info-col h2 { color: #fff; }
.contact-list li { display: flex; gap: var(--space-3); padding: var(--space-3) 0; border-bottom: 1px solid rgba(148,163,184,.18); }
.contact-list li:last-child { border-bottom: 0; }
.contact-list .ico { color: #7DD3FC; margin-top: 4px; width: 20px; height: 20px; }
.contact-list strong { display: block; color: #E2E8F0; font-size: .85rem; text-transform: uppercase; letter-spacing: .05em; margin-bottom: 2px; }
.contact-list a { color: #E2E8F0; }
.contact-list a:hover { color: #7DD3FC; }

/* faq */
.faq-section { background: var(--surface); border-top: 1px solid var(--border); }
.faq-list { display: flex; flex-direction: column; gap: var(--space-3); margin-top: var(--space-5); }
.faq-item { border: 1px solid var(--border); border-radius: var(--radius); background: var(--bg); overflow: hidden; }
.faq-item summary {
  display: flex; justify-content: space-between; align-items: center; gap: var(--space-4);
  padding: var(--space-4) var(--space-5); cursor: pointer; font-weight: 600; color: var(--primary);
  list-style: none; min-height: 48px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary .ico { transition: transform .2s var(--ease); color: var(--accent); }
.faq-item[open] summary .ico { transform: rotate(180deg); }
.faq-item summary:hover { background: var(--accent-soft); }
.faq-a { padding: 0 var(--space-5) var(--space-5); color: var(--secondary); }
.faq-a p { margin: 0; }

/* ------------------------------- footer ----------------------------- */
.site-footer { background: var(--primary); color: #94A3B8; margin-top: var(--space-8); }
.site-footer .footer-grid {
  display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.3fr; gap: var(--space-6);
  padding-block: var(--space-8) var(--space-6);
}
.site-footer h3 { color: #E2E8F0; font-size: 1rem; margin-bottom: var(--space-4); }
.footer-about p { font-size: .92rem; }
.footer-col ul { display: flex; flex-direction: column; gap: 10px; font-size: .94rem; }
.footer-col a { color: #CBD5E1; }
.footer-col a:hover { color: #7DD3FC; }
.footer-contact li { display: flex; gap: 10px; align-items: flex-start; }
.footer-contact .ico { color: #7DD3FC; margin-top: 4px; flex: none; }
.footer-contact li > span, .footer-contact li > a { display: block; }
.site-footer .cert-chip { background: rgba(255,255,255,.06); border-color: rgba(148,163,184,.25); color: #CBD5E1; }
.site-footer .cert-chip .ico { color: #7DD3FC; }
.footer-bottom { border-top: 1px solid rgba(148,163,184,.18); }
.footer-bottom-inner { display: flex; justify-content: space-between; gap: var(--space-4); padding-block: var(--space-4); font-size: .84rem; flex-wrap: wrap; }
.footer-bottom p { margin: 0; }
.footer-note { opacity: .7; }

.to-top {
  position: fixed; right: 22px; bottom: 22px; z-index: 900;
  width: 48px; height: 48px; border-radius: 50%;
  background: var(--accent); color: #fff; border: 0; cursor: pointer;
  display: grid; place-items: center; box-shadow: var(--shadow);
  opacity: 0; visibility: hidden; transform: translateY(8px);
  transition: opacity .2s var(--ease), transform .2s var(--ease), visibility .2s, background .2s;
}
.to-top.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }
.to-top:hover { background: var(--accent-strong); }
.to-top .ico { width: 20px; height: 20px; }

/* ------------------------------- 404 -------------------------------- */
.notfound { text-align: center; padding-block: var(--space-9); }
.notfound-code { font-size: clamp(4rem, 3rem + 6vw, 7rem); font-weight: 700; color: var(--accent); margin: 0; line-height: 1; }
.notfound .hero-cta { justify-content: center; margin-top: var(--space-5); }

/* ---------------------------- reveal anim ---------------------------- */
.reveal { opacity: 0; transform: translateY(16px); transition: opacity .45s var(--ease), transform .45s var(--ease); }
.reveal.in-view { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; } }

/* ----------------------------- responsive ---------------------------- */
@media (max-width: 1024px) {
  .page-body-layout { grid-template-columns: 1fr; }
  .side-nav { position: static; flex-direction: column; }
  .side-nav ul { flex-direction: row; flex-wrap: wrap; }
  .side-cta { max-width: 420px; }
  .product-layout { grid-template-columns: 1fr; }
  .product-media-col { max-width: 480px; }
  .app-section { grid-template-columns: 1fr; }
  .app-body { padding: var(--space-5); }
  .about-mission, .about-factory { grid-template-columns: 1fr; }
  .contact-layout { grid-template-columns: 1fr; }
  .site-footer .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 640px) {
  :root { --header-h: 62px; }
  .section { padding-block: var(--space-7); }
  .hero-inner { padding-block: var(--space-7); }
  .stats-inner { grid-template-columns: repeat(2, 1fr); }
  .form-row { grid-template-columns: 1fr; }
  .product-cols { grid-template-columns: 1fr; }
  .mega-grid ul { grid-template-columns: 1fr; }
  .site-footer .footer-grid { grid-template-columns: 1fr; gap: var(--space-5); }
  .footer-bottom-inner { flex-direction: column; }
  .card-grid { grid-template-columns: 1fr 1fr; gap: var(--space-3); }
  .card-body { padding: var(--space-3) var(--space-4) var(--space-4); }
  .card-sub { display: none; }
  .news-grid, .news-grid-2 { grid-template-columns: 1fr; }
  .cat-grid { grid-template-columns: 1fr; }
}

@media (max-width: 420px) {
  .card-grid { grid-template-columns: 1fr; }
}