/* Guolian Inorganic Silicates — site styles */
:root {
  --bg: #f5f7f8;
  --surface: #ffffff;
  --ink: #0e1b22;
  --ink-2: #2b3c45;
  --muted: #5a6b74;
  --line: #d6dfe3;
  --line-strong: #b9c7cd;
  --accent: #17607c;
  --accent-ink: #0d4258;
  --opal: #cfe4ee;
  --opal-2: #e9f3f7;
  --warn: #8a5a12;
  --warn-bg: #fbf3e4;
  --radius: 6px;
  --maxw: 1160px;
  --font: "Instrument Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "Cascadia Mono", Consolas, monospace;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.6;
}
img, svg { max-width: 100%; height: auto; }
a { color: var(--accent); text-underline-offset: 3px; }
a:hover { color: var(--accent-ink); }
h1, h2, h3, h4 { line-height: 1.2; letter-spacing: -0.01em; margin: 0 0 .6em; }
h1 { font-size: clamp(2rem, 4.2vw, 3.1rem); font-weight: 600; }
h2 { font-size: clamp(1.5rem, 2.6vw, 2rem); font-weight: 600; }
h3 { font-size: 1.2rem; font-weight: 600; }
p { margin: 0 0 1em; }
code, .mono { font-family: var(--mono); font-size: .9em; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
@media (max-width: 600px) { .wrap { padding: 0 16px; } }

.skip { position: absolute; left: -999px; }
.skip:focus { left: 16px; top: 16px; background: #fff; padding: 8px 12px; z-index: 100; }

/* ---------- header ---------- */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 50;
}
.site-header .wrap { display: flex; align-items: center; gap: 24px; min-height: 68px; }
.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; color: var(--ink); }
.brand-mark { width: 34px; height: 34px; flex: none; }
.brand-name { font-weight: 700; letter-spacing: .14em; font-size: 1.05rem; }
.brand-sub { display: block; white-space: nowrap; font-family: var(--mono); font-size: .66rem; letter-spacing: .06em; color: var(--muted); text-transform: uppercase; }
.nav { margin-left: auto; display: flex; align-items: center; gap: 4px; }
.nav > a, .nav-group > button {
  font: inherit; font-size: .93rem; color: var(--ink-2); text-decoration: none;
  padding: 8px 12px; border-radius: var(--radius); background: none; border: 0; cursor: pointer;
}
.nav > a:hover, .nav-group > button:hover, .nav > a[aria-current="page"] { background: var(--opal-2); color: var(--accent-ink); }
.nav-group { position: relative; }
.nav-group > button::after { content: "▾"; font-size: .7em; margin-left: 6px; }
.nav-menu {
  display: none; position: absolute; top: 100%; left: 0; min-width: 270px;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  box-shadow: 0 12px 30px rgba(14, 27, 34, .1); padding: 6px;
}
.nav-group:hover .nav-menu, .nav-group:focus-within .nav-menu { display: block; }
.nav-menu a { display: block; padding: 8px 12px; border-radius: 4px; color: var(--ink-2); text-decoration: none; font-size: .93rem; }
.nav-menu a small { display: block; color: var(--muted); font-size: .78rem; }
.nav-menu a:hover { background: var(--opal-2); }
.nav > a.btn { margin-left: 8px; color: #fff; background: var(--accent); padding: 9px 16px; }
.nav > a.btn:hover { background: var(--accent-ink); color: #fff; }
.nav-toggle { display: none; margin-left: auto; background: none; border: 1px solid var(--line); border-radius: var(--radius); padding: 8px 12px; font: inherit; }

@media (max-width: 920px) {
  .nav-toggle { display: block; }
  .nav {
    display: none; position: absolute; left: 0; right: 0; top: 100%;
    background: var(--surface); border-bottom: 1px solid var(--line);
    flex-direction: column; align-items: stretch; padding: 8px 16px 16px; gap: 0;
  }
  .nav.open { display: flex; }
  .nav-group > button { display: none; }
  .nav-menu { display: block; position: static; border: 0; box-shadow: none; padding: 0; min-width: 0; }
  .nav-menu a small { display: none; }
  .nav .btn { margin: 10px 0 0; text-align: center; }
}

/* ---------- buttons ---------- */
.btn {
  display: inline-block; font: inherit; font-weight: 600; font-size: .95rem;
  padding: 11px 20px; border-radius: var(--radius); text-decoration: none; cursor: pointer;
  background: var(--accent); color: #fff; border: 1px solid var(--accent);
}
.btn:hover { background: var(--accent-ink); color: #fff; }
.btn-ghost { background: transparent; color: var(--accent); }
.btn-ghost:hover { background: var(--opal-2); color: var(--accent-ink); }

/* ---------- sections ---------- */
section { padding: 72px 0; }
section + section { border-top: 1px solid var(--line); }
.eyebrow {
  font-family: var(--mono); font-size: .75rem; letter-spacing: .1em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 12px; display: block;
}
.lead { font-size: 1.15rem; color: var(--ink-2); max-width: 62ch; }
.muted { color: var(--muted); }
.prose { max-width: 72ch; }
.prose h2 { margin-top: 1.6em; }
.prose h3 { margin-top: 1.4em; }
.prose ul, .prose ol { padding-left: 1.2em; }
.prose li { margin-bottom: .4em; }

/* hero */
.hero { padding: 80px 0 64px; background: linear-gradient(180deg, var(--surface) 0%, var(--bg) 100%); }
.hero .wrap { display: grid; grid-template-columns: 1.15fr .85fr; gap: 48px; align-items: center; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 28px; }
.hero-figure { background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 20px; }
.hero-figure figcaption { font-family: var(--mono); font-size: .72rem; color: var(--muted); margin-top: 10px; }
@media (max-width: 860px) { .hero .wrap { grid-template-columns: 1fr; } .hero { padding: 48px 0; } }

.page-hero { padding: 56px 0 40px; background: var(--surface); border-bottom: 1px solid var(--line); }
.page-hero + section { border-top: 0; }
.crumbs { font-size: .85rem; color: var(--muted); margin-bottom: 18px; }
.crumbs a { color: var(--muted); }

/* facts strip */
.facts { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
.facts div { padding: 18px 20px; border-left: 1px solid var(--line); }
.facts div:first-child { border-left: 0; }
.facts b { display: block; font-family: var(--mono); font-size: 1.35rem; font-weight: 500; color: var(--accent-ink); }
.facts span { font-size: .85rem; color: var(--muted); }
@media (max-width: 760px) {
  .facts { grid-template-columns: 1fr 1fr; }
  .facts div:nth-child(3) { border-left: 0; }
  .facts div:nth-child(n+3) { border-top: 1px solid var(--line); }
}

/* cards */
.grid { display: grid; gap: 20px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 900px) { .grid-3 { grid-template-columns: 1fr 1fr; } }
@media (max-width: 640px) { .grid-3, .grid-2 { grid-template-columns: 1fr; } }
.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px; display: flex; flex-direction: column;
}
.card h3 { margin-bottom: .35em; }
.card .code { font-family: var(--mono); font-size: .78rem; color: var(--accent); letter-spacing: .04em; margin-bottom: 10px; }
.card p { color: var(--ink-2); font-size: .97rem; }
.card .more { margin-top: auto; font-weight: 600; font-size: .93rem; text-decoration: none; }
.card .more::after { content: " →"; }
a.card { text-decoration: none; color: inherit; transition: border-color .15s; }
a.card:hover { border-color: var(--accent); }

/* spec tables */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); margin: 0 0 1.2em; }
table { border-collapse: collapse; width: 100%; font-size: .93rem; }
th, td { text-align: left; padding: 10px 14px; border-bottom: 1px solid var(--line); vertical-align: top; }
thead th { background: var(--opal-2); font-weight: 600; font-size: .82rem; color: var(--ink-2); white-space: nowrap; }
tbody tr:last-child td, tbody tr:last-child th { border-bottom: 0; }
td.num, td .num { font-family: var(--mono); font-size: .88rem; white-space: nowrap; }
tbody th { font-weight: 600; white-space: nowrap; }
.tds { font-family: var(--mono); font-size: .78rem; color: var(--warn); background: var(--warn-bg); padding: 1px 6px; border-radius: 3px; white-space: nowrap; }
.table-note { font-size: .85rem; color: var(--muted); max-width: 80ch; }

dl.spec { display: grid; grid-template-columns: minmax(140px, 220px) 1fr; margin: 0 0 1.2em; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); }
dl.spec dt, dl.spec dd { padding: 10px 14px; border-bottom: 1px solid var(--line); margin: 0; }
dl.spec dt { color: var(--muted); font-size: .9rem; }
dl.spec dd { font-size: .95rem; }
dl.spec dt:last-of-type, dl.spec dd:last-of-type { border-bottom: 0; }
@media (max-width: 560px) { dl.spec { grid-template-columns: 1fr; } dl.spec dt { border-bottom: 0; padding-bottom: 0; } }

/* callouts */
.note { border-left: 3px solid var(--accent); background: var(--opal-2); padding: 14px 18px; border-radius: 0 var(--radius) var(--radius) 0; margin: 0 0 1.4em; font-size: .95rem; }
.note.warn { border-color: var(--warn); background: var(--warn-bg); }

/* two-column layout for product pages */
.split { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 48px; align-items: start; }
.aside { position: sticky; top: 92px; display: flex; flex-direction: column; gap: 16px; }
.aside .card { padding: 20px; }
.aside h4 { font-size: .8rem; font-family: var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--muted); margin-bottom: 10px; }
.aside ul { list-style: none; padding: 0; margin: 0; font-size: .93rem; }
.aside li { padding: 5px 0; border-bottom: 1px dashed var(--line); }
.aside li:last-child { border-bottom: 0; }
@media (max-width: 900px) { .split { grid-template-columns: minmax(0, 1fr); } .aside { position: static; } }

/* FAQ */
.faq details { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 0 18px; margin-bottom: 10px; }
.faq summary { cursor: pointer; padding: 14px 0; font-weight: 600; list-style: none; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; float: right; color: var(--accent); font-family: var(--mono); }
.faq details[open] summary::after { content: "−"; }
.faq details > div { padding-bottom: 14px; color: var(--ink-2); }

/* tool */
.tool { background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 24px; }
.tool .fields { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
@media (max-width: 700px) { .tool .fields { grid-template-columns: 1fr; } }
label { display: block; font-size: .85rem; font-weight: 600; color: var(--ink-2); margin-bottom: 6px; }
input, select, textarea {
  width: 100%; font: inherit; font-size: .97rem; padding: 10px 12px; color: var(--ink);
  border: 1px solid var(--line-strong); border-radius: var(--radius); background: #fff;
}
input:focus, select:focus, textarea:focus { outline: 2px solid var(--opal); border-color: var(--accent); }
.tool-out { margin-top: 20px; padding: 16px 18px; background: var(--opal-2); border-radius: var(--radius); font-size: .97rem; }
.tool-out b { font-family: var(--mono); font-weight: 500; color: var(--accent-ink); font-size: 1.15rem; }

/* form */
.form { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form .full { grid-column: 1 / -1; }
@media (max-width: 640px) { .form { grid-template-columns: 1fr; } }
.form-status { font-size: .93rem; }
.hp { position: absolute; left: -9999px; }

/* CTA band */
.cta-band { background: var(--ink); color: #e6eef1; }
.cta-band h2 { color: #fff; }
.cta-band p { color: #b9c8ce; }
.cta-band .wrap { display: flex; gap: 32px; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.cta-band .btn { background: #fff; color: var(--ink); border-color: #fff; }
.cta-band .btn:hover { background: var(--opal); }

/* footer */
.site-footer { background: #0a141a; color: #9fb1b9; font-size: .9rem; padding: 56px 0 28px; }
.site-footer a { color: #cbd8de; text-decoration: none; }
.site-footer a:hover { color: #fff; text-decoration: underline; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 32px; }
.footer-grid h4 { color: #fff; font-size: .78rem; font-family: var(--mono); letter-spacing: .1em; text-transform: uppercase; margin-bottom: 14px; }
.footer-grid ul { list-style: none; padding: 0; margin: 0; }
.footer-grid li { margin-bottom: 8px; }
.footer-base { border-top: 1px solid #1d2b33; margin-top: 40px; padding-top: 20px; display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; font-size: .8rem; }
@media (max-width: 860px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 520px) { .footer-grid { grid-template-columns: 1fr; } }

@media (max-width: 420px) { .brand-sub { display: none; } section { padding: 52px 0; } }
.grid > * { min-width: 0; }

/* images */
.figure { margin: 0 0 1.6em; }
.figure img { display: block; width: 100%; height: auto; aspect-ratio: 16 / 9; object-fit: cover; border-radius: var(--radius); border: 1px solid var(--line); background: var(--opal-2); }
.figure figcaption { font-size: .8rem; color: var(--muted); margin-top: 8px; }
.page-hero.with-image .wrap { display: grid; grid-template-columns: 1.1fr .9fr; gap: 40px; align-items: center; }
.page-hero.with-image .figure { margin: 0; }
@media (max-width: 860px) { .page-hero.with-image .wrap { grid-template-columns: minmax(0, 1fr); } }
.card-img { margin: -24px -24px 18px; }
.card-img img { display: block; width: 100%; aspect-ratio: 16 / 9; object-fit: cover; border-radius: var(--radius) var(--radius) 0 0; }
.diagram { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; margin: 0 0 1.6em; }
.diagram figcaption { font-size: .8rem; color: var(--muted); margin-top: 8px; }
.nav-head { display: block; padding: 10px 12px 2px; font-family: var(--mono); font-size: .68rem; letter-spacing: .1em; text-transform: uppercase; color: var(--muted); }
.nav-menu .nav-head:first-child { padding-top: 4px; }
.nav-group:last-of-type .nav-menu { columns: 2; column-gap: 8px; min-width: 520px; }
.nav-group:last-of-type .nav-menu > * { break-inside: avoid; }
@media (max-width: 920px) { .nav-group:last-of-type .nav-menu { columns: 1; min-width: 0; } }
.nav-group:last-of-type .nav-menu { left: auto; right: 0; }
.group-title { font-family: var(--mono); font-size: .8rem; font-weight: 500; letter-spacing: .1em; text-transform: uppercase; color: var(--accent); margin: 36px 0 14px; padding-top: 14px; border-top: 1px solid var(--line); }
#applications h2 + .group-title { margin-top: 24px; }
.lang-switch { flex: none; padding: 5px 11px; border: 1px solid var(--line-strong); border-radius: 999px; font-size: .82rem; font-weight: 600; color: var(--ink-2); text-decoration: none; }
.lang-switch:hover { border-color: var(--accent); color: var(--accent-ink); background: var(--opal-2); }
@media (max-width: 920px) { .site-header .wrap { gap: 10px; } }
.hero-photo img { aspect-ratio: 3 / 2; }
/* larger industry group headings and eyebrow labels (v2) */
.group-title { font-family: var(--font); font-size: 1.35rem; font-weight: 700; letter-spacing: 0; text-transform: none; color: var(--ink); margin: 44px 0 16px; padding: 0 0 0 12px; border-top: 0; border-left: 4px solid var(--accent); line-height: 1.25; }
#applications h2 + .group-title { margin-top: 28px; }
.eyebrow { font-size: .82rem; }
:lang(zh) .eyebrow { font-family: var(--font); font-size: .9rem; letter-spacing: .06em; font-weight: 600; }
/* home trust strip */
.facts.trust b { font-family: var(--font); font-size: 1.25rem; font-weight: 700; }
.facts.trust .medal { display: flex; align-items: center; gap: 12px; }
.facts.trust .medal img { width: 64px; height: 64px; flex: none; }
.facts.trust .medal b { display: block; }
.facts.trust { grid-template-columns: repeat(5, 1fr); }
@media (max-width: 900px) { .facts.trust { grid-template-columns: 1fr 1fr; } .facts.trust div { border-left: 0; border-top: 1px solid var(--line); } }