/* McVern — Premium Navy/Steel Industrial B2B
   Mobile-first · Cloudflare Pages static */

:root {
  --navy-950: #060f1a;
  --navy-900: #0b1f33;
  --navy-800: #0f2740;
  --navy-700: #132b44;
  --navy-600: #1a3a55;
  --steel-500: #5a8fa8;
  --steel-400: #7eb8d4;
  --steel-300: #8ba3b5;
  --steel-200: #c5d4de;
  --steel-100: #e8f0f5;
  --gold: #c9a227;
  --gold-dim: #a68420;
  --surface: #0f2740;
  --card: #132b44;
  --border: #2a3f52;
  --text: #e8f0f5;
  --muted: #8ba3b5;
  --radius: 10px;
  --shadow: 0 8px 32px rgba(0,0,0,.35);
  --font: "Segoe UI", "Helvetica Neue", system-ui, -apple-system, sans-serif;
  --mono: ui-monospace, "SF Mono", Consolas, monospace;
  --max: 1120px;
  --header-h: 68px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  background: var(--navy-950);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

img, svg { max-width: 100%; height: auto; display: block; }
a { color: var(--steel-400); text-decoration: none; transition: color .2s; }
a:hover { color: var(--gold); }
ul { list-style: none; }
button, input, select, textarea { font: inherit; }

.container {
  width: min(100% - 2rem, var(--max));
  margin-inline: auto;
}

/* —— Header —— */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(11, 31, 51, .92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  height: var(--header-h);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  gap: 1rem;
}

.logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}
.logo img, .logo svg {
  height: 36px;
  width: auto;
  object-fit: contain;
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 8px 10px;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--steel-100);
  transition: transform .25s, opacity .25s;
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.nav {
  position: fixed;
  inset: var(--header-h) 0 auto 0;
  background: var(--navy-900);
  border-bottom: 1px solid var(--border);
  padding: 1rem;
  display: none;
  flex-direction: column;
  gap: .25rem;
  box-shadow: var(--shadow);
}
.nav.is-open { display: flex; }

.nav a {
  color: var(--steel-100);
  padding: .75rem 1rem;
  border-radius: 6px;
  font-weight: 500;
  font-size: .95rem;
}
.nav a:hover, .nav a.active {
  background: var(--navy-600);
  color: var(--steel-400);
}

.lang-toggle {
  display: inline-flex;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
  margin-top: .5rem;
  align-self: flex-start;
}
.lang-toggle button {
  background: transparent;
  border: none;
  color: var(--muted);
  padding: .4rem .75rem;
  cursor: pointer;
  font-size: .8rem;
  font-weight: 600;
}
.lang-toggle button.active {
  background: var(--navy-600);
  color: var(--steel-400);
}

.header-actions {
  display: none;
  align-items: center;
  gap: .75rem;
}

/* —— Buttons —— */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  padding: .75rem 1.4rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: .95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background .2s, border-color .2s, transform .15s;
}
.btn:active { transform: scale(.98); }
.btn-primary {
  background: var(--steel-400);
  color: var(--navy-950);
}
.btn-primary:hover {
  background: var(--steel-200);
  color: var(--navy-950);
}
.btn-ghost {
  background: transparent;
  border-color: var(--border);
  color: var(--steel-100);
}
.btn-ghost:hover {
  border-color: var(--steel-400);
  color: var(--steel-400);
}
.btn-gold {
  background: var(--gold);
  color: var(--navy-950);
}
.btn-gold:hover { background: #dbb52e; color: var(--navy-950); }

/* —— Hero —— */
.hero {
  position: relative;
  padding: 3.5rem 0 4rem;
  background:
    radial-gradient(ellipse 80% 60% at 70% 20%, rgba(90,143,168,.18), transparent),
    linear-gradient(180deg, var(--navy-900) 0%, var(--navy-950) 100%);
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(126,184,212,.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(126,184,212,.04) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
}
.hero-grid {
  display: grid;
  gap: 2.5rem;
  position: relative;
}
.hero-badge {
  display: inline-block;
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--gold);
  border: 1px solid rgba(201,162,39,.4);
  padding: .35rem .75rem;
  border-radius: 999px;
  margin-bottom: 1.25rem;
}
.hero h1 {
  font-size: clamp(1.75rem, 5vw, 2.75rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -.02em;
  margin-bottom: 1rem;
  max-width: 18ch;
}
.hero .lede {
  font-size: 1.05rem;
  color: var(--muted);
  max-width: 42ch;
  margin-bottom: 1.75rem;
}
.hero-cta { display: flex; flex-wrap: wrap; gap: .75rem; }
.hero-visual {
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--card);
  overflow: hidden;
  box-shadow: var(--shadow);
}
.hero-visual img { width: 100%; }

.trust-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  position: relative;
}
.trust-item {
  font-size: .85rem;
  color: var(--muted);
}
.trust-item strong {
  display: block;
  color: var(--steel-100);
  font-size: .95rem;
  margin-bottom: .15rem;
}

/* —— Sections —— */
section { padding: 3.5rem 0; }
.section-head {
  margin-bottom: 2rem;
}
.section-eyebrow {
  font-size: .75rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--steel-400);
  margin-bottom: .5rem;
}
.section-head h2 {
  font-size: clamp(1.5rem, 3.5vw, 2rem);
  font-weight: 700;
  margin-bottom: .75rem;
}
.section-head p {
  color: var(--muted);
  max-width: 56ch;
}

.alt-bg {
  background: var(--navy-900);
  border-block: 1px solid var(--border);
}

/* —— Cards —— */
.card-grid {
  display: grid;
  gap: 1.25rem;
  grid-template-columns: 1fr;
}
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color .2s, transform .2s;
}
.card:hover {
  border-color: var(--steel-500);
  transform: translateY(-2px);
}
.card-img { background: var(--navy-800); }
.card-img img, .card-img svg { width: 100%; aspect-ratio: 16/10; object-fit: cover; }
.card-body { padding: 1.25rem 1.35rem 1.5rem; }
.card-body h3 {
  font-size: 1.15rem;
  margin-bottom: .5rem;
}
.card-body p {
  color: var(--muted);
  font-size: .95rem;
  margin-bottom: .75rem;
}
.card-meta {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem;
  margin-top: .75rem;
}
.tag {
  font-size: .7rem;
  font-weight: 600;
  letter-spacing: .04em;
  text-transform: uppercase;
  padding: .25rem .55rem;
  border-radius: 4px;
  background: var(--navy-600);
  color: var(--steel-400);
  border: 1px solid var(--border);
}
.tag-gold {
  background: rgba(201,162,39,.15);
  color: var(--gold);
  border-color: rgba(201,162,39,.35);
}

/* —— Knowledge / definition —— */
.def-list {
  display: grid;
  gap: 1rem;
}
.def-item {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.35rem;
}
.def-item h4 {
  font-size: 1rem;
  color: var(--steel-400);
  margin-bottom: .4rem;
}
.def-item p { color: var(--muted); font-size: .92rem; }

/* —— Example callout —— */
.example-banner {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  font-family: var(--mono);
  font-size: .75rem;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--gold);
  background: rgba(201,162,39,.12);
  border: 1px solid rgba(201,162,39,.35);
  padding: .35rem .7rem;
  border-radius: 4px;
  margin-bottom: 1rem;
}

/* —— Split / features —— */
.feature-row {
  display: grid;
  gap: 1.5rem;
}
.feature {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}
.feature-icon {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  border-radius: 8px;
  background: var(--navy-600);
  border: 1px solid var(--border);
  display: grid;
  place-items: center;
  color: var(--steel-400);
  font-size: 1.2rem;
}
.feature h3 { font-size: 1.05rem; margin-bottom: .3rem; }
.feature p { color: var(--muted); font-size: .92rem; }

/* —— Table —— */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
table {
  width: 100%;
  border-collapse: collapse;
  font-size: .9rem;
}
th, td {
  padding: .85rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
th {
  background: var(--navy-800);
  color: var(--steel-400);
  font-weight: 600;
  white-space: nowrap;
}
td { color: var(--muted); background: var(--card); }
tr:last-child td { border-bottom: none; }

/* —— Form —— */
.form-grid {
  display: grid;
  gap: 1rem;
}
.form-group label {
  display: block;
  font-size: .85rem;
  font-weight: 600;
  margin-bottom: .35rem;
  color: var(--steel-200);
}
.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  background: var(--navy-800);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: .75rem 1rem;
  color: var(--text);
  outline: none;
  transition: border-color .2s;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--steel-400);
}
.form-group textarea { min-height: 120px; resize: vertical; }
.checklist {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.35rem;
}
.checklist h3 { margin-bottom: .75rem; font-size: 1.05rem; }
.checklist li {
  position: relative;
  padding-left: 1.4rem;
  margin-bottom: .5rem;
  color: var(--muted);
  font-size: .92rem;
}
.checklist li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--steel-400);
  font-weight: 700;
}

.contact-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
}
.contact-card h3 { margin-bottom: .75rem; }
.contact-row {
  display: flex;
  flex-direction: column;
  gap: .35rem;
  margin-bottom: 1rem;
  font-size: .95rem;
}
.contact-row span { color: var(--muted); font-size: .8rem; }
.contact-row a { color: var(--steel-400); font-weight: 600; }

/* —— CTA band —— */
.cta-band {
  background:
    linear-gradient(135deg, var(--navy-700), var(--navy-900));
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.5rem 1.75rem;
  text-align: center;
}
.cta-band h2 { margin-bottom: .75rem; }
.cta-band p {
  color: var(--muted);
  margin-bottom: 1.5rem;
  max-width: 48ch;
  margin-inline: auto;
}

/* —— Footer —— */
.site-footer {
  background: var(--navy-900);
  border-top: 1px solid var(--border);
  padding: 2.5rem 0 1.5rem;
  margin-top: 2rem;
}
.footer-grid {
  display: grid;
  gap: 2rem;
  margin-bottom: 2rem;
}
.footer-brand p {
  color: var(--muted);
  font-size: .9rem;
  margin-top: .75rem;
  max-width: 32ch;
}
.footer-col h4 {
  font-size: .8rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--steel-400);
  margin-bottom: .75rem;
}
.footer-col a {
  display: block;
  color: var(--muted);
  font-size: .9rem;
  padding: .25rem 0;
}
.footer-col a:hover { color: var(--steel-100); }
.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 1.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  justify-content: space-between;
  font-size: .8rem;
  color: var(--muted);
}
.disclaimer {
  font-size: .75rem;
  color: var(--steel-300);
  opacity: .8;
  max-width: 60ch;
}

/* —— Documentation page —— */
.doc-img {
  position: relative;
}
.doc-example-badge {
  position: absolute;
  top: .65rem;
  left: .65rem;
  z-index: 2;
  font-family: var(--mono);
  font-size: .68rem;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--gold);
  background: rgba(6, 15, 26, .82);
  border: 1px solid rgba(201, 162, 39, .45);
  padding: .28rem .55rem;
  border-radius: 4px;
}
.doc-catalogue {
  display: grid;
  gap: .65rem;
  grid-template-columns: 1fr;
}
.doc-catalogue li {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: .85rem 1.1rem;
  color: var(--steel-200);
  font-size: .95rem;
  position: relative;
  padding-left: 1.75rem;
}
.doc-catalogue li::before {
  content: "▸";
  position: absolute;
  left: .75rem;
  color: var(--steel-400);
  font-weight: 700;
}
.lang-caps {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
}
.lang-pill {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: .45rem .9rem;
  font-size: .85rem;
  color: var(--muted);
}
.lang-pill strong {
  color: var(--steel-400);
  font-size: .8rem;
  letter-spacing: .04em;
}
.process-strip {
  display: grid;
  gap: .75rem;
  grid-template-columns: 1fr;
  list-style: none;
  counter-reset: none;
}
.process-strip li {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.15rem;
  display: flex;
  flex-direction: column;
  gap: .35rem;
}
.process-num {
  font-family: var(--mono);
  font-size: .75rem;
  font-weight: 700;
  color: var(--gold);
  letter-spacing: .04em;
}
.process-strip strong {
  font-size: .95rem;
  color: var(--text);
  font-weight: 600;
}

/* —— Page hero (inner) —— */
.page-hero {
  padding: 2.5rem 0 2rem;
  background: linear-gradient(180deg, var(--navy-900), var(--navy-950));
  border-bottom: 1px solid var(--border);
}
.page-hero h1 {
  font-size: clamp(1.6rem, 4vw, 2.25rem);
  margin-bottom: .5rem;
}
.page-hero p { color: var(--muted); max-width: 52ch; }

/* —— Lang content —— */
[data-lang-zh] { display: none !important; }
html[lang="zh"] [data-lang-en] { display: none !important; }
html[lang="zh"] [data-lang-zh] { display: revert !important; }
/* Block-level bilingual twins (sibling elements) */
html[lang="zh"] h1[data-lang-zh],
html[lang="zh"] h2[data-lang-zh],
html[lang="zh"] h3[data-lang-zh],
html[lang="zh"] h4[data-lang-zh],
html[lang="zh"] p[data-lang-zh],
html[lang="zh"] label[data-lang-zh],
html[lang="zh"] li[data-lang-zh],
html[lang="zh"] strong[data-lang-zh],
html[lang="zh"] a.btn[data-lang-zh],
html[lang="zh"] button.btn[data-lang-zh] { display: block !important; }
html[lang="zh"] a.btn[data-lang-zh],
html[lang="zh"] button.btn[data-lang-zh] { display: inline-flex !important; }
html[lang="zh"] .nav a[data-lang-zh] { display: block !important; }
@media (min-width: 768px) {
  html[lang="zh"] .nav a[data-lang-zh] { display: inline-block !important; }
}

/* —— Desktop —— */
@media (min-width: 768px) {
  .nav-toggle { display: none; }
  .nav {
    position: static;
    display: flex !important;
    flex-direction: row;
    align-items: center;
    background: none;
    border: none;
    box-shadow: none;
    padding: 0;
    gap: .15rem;
  }
  .nav a {
    padding: .5rem .7rem;
    font-size: .875rem;
  }
  .lang-toggle {
    margin-top: 0;
    margin-left: .5rem;
  }
  .header-actions { display: flex; }
  .hero-grid {
    grid-template-columns: 1.1fr .9fr;
    align-items: center;
  }
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .card-grid.cols-3 {
    grid-template-columns: repeat(3, 1fr);
  }
  .def-list {
    grid-template-columns: repeat(2, 1fr);
  }
  .feature-row {
    grid-template-columns: repeat(2, 1fr);
  }
  .doc-catalogue {
    grid-template-columns: 1fr 1fr;
  }
  .process-strip {
    grid-template-columns: repeat(3, 1fr);
  }
  .form-grid.two {
    grid-template-columns: 1fr 1fr;
  }
  .contact-layout {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 2rem;
    align-items: start;
  }
  .footer-grid {
    grid-template-columns: 1.4fr 1fr 1fr 1fr;
  }
  .split-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .card-grid.cols-3 {
    grid-template-columns: repeat(3, 1fr);
  }
  .process-strip {
    grid-template-columns: repeat(6, 1fr);
  }
  .doc-catalogue {
    grid-template-columns: repeat(3, 1fr);
  }
  .nav a { padding: .5rem .85rem; }
}