/* ============================================================
   Suzhou Boyuan Special Transformer Co., Ltd.
   https://transformer.omio.top  — Shared Stylesheet
   ============================================================ */
:root {
  --navy: #0b1f3a;
  --navy-2: #122c4f;
  --navy-3: #1a3a63;
  --gold: #f5a623;
  --gold-dark: #d98d0b;
  --ink: #1d2733;
  --muted: #5b6b7c;
  --line: #e3e8ee;
  --bg-soft: #f5f7fa;
  --white: #ffffff;
  --radius: 10px;
  --shadow: 0 10px 30px rgba(11, 31, 58, .10);
  --shadow-sm: 0 4px 14px rgba(11, 31, 58, .08);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'Sarabun', 'Segoe UI', Tahoma, sans-serif;
  color: var(--ink);
  background: var(--white);
  line-height: 1.75;
  font-size: 16px;
}

img { max-width: 100%; height: auto; display: block; }

h1, h2, h3, h4 { font-family: 'Prompt', 'Sarabun', sans-serif; color: var(--navy); line-height: 1.35; }

a { color: var(--navy-3); text-decoration: none; transition: color .2s; }
a:hover { color: var(--gold-dark); }

.container { max-width: 1180px; margin: 0 auto; padding: 0 20px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 13px 32px;
  border-radius: 50px;
  font-family: 'Prompt', sans-serif;
  font-weight: 600;
  font-size: 16px;
  cursor: pointer;
  border: 2px solid transparent;
  transition: all .25s;
  text-align: center;
}
.btn-gold { background: var(--gold); color: var(--navy); }
.btn-gold:hover { background: #ffb838; color: var(--navy); transform: translateY(-2px); box-shadow: 0 8px 20px rgba(245, 166, 35, .35); }
.btn-outline { border-color: var(--white); color: var(--white); }
.btn-outline:hover { background: var(--white); color: var(--navy); }
.btn-navy { background: var(--navy); color: var(--white); }
.btn-navy:hover { background: var(--navy-3); color: var(--white); transform: translateY(-2px); }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--white);
  box-shadow: 0 2px 12px rgba(11, 31, 58, .08);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 78px; }
.brand { display: flex; align-items: center; gap: 12px; }
.brand img { width: 44px; height: auto; }
.brand-text { display: flex; flex-direction: column; line-height: 1.25; }
.brand-text strong { font-family: 'Prompt', sans-serif; font-size: 18px; color: var(--navy); }
.brand-text small { font-size: 11px; letter-spacing: 1.5px; color: var(--muted); text-transform: uppercase; }

.nav-toggle { display: none; }
.nav-burger { display: none; width: 42px; height: 42px; cursor: pointer; position: relative; }
.nav-burger span, .nav-burger span::before, .nav-burger span::after {
  content: ""; position: absolute; left: 9px; width: 24px; height: 2.5px;
  background: var(--navy); border-radius: 2px; transition: all .25s;
}
.nav-burger span { top: 20px; }
.nav-burger span::before { top: -8px; left: 0; }
.nav-burger span::after { top: 8px; left: 0; }

.site-nav { display: flex; align-items: center; gap: 28px; }
.site-nav > a { font-family: 'Prompt', sans-serif; font-weight: 500; font-size: 15.5px; color: var(--ink); padding: 6px 0; position: relative; }
.site-nav > a::after {
  content: ""; position: absolute; left: 0; bottom: -2px; width: 0; height: 2.5px;
  background: var(--gold); transition: width .25s; border-radius: 2px;
}
.site-nav > a:hover::after, .site-nav > a.active::after { width: 100%; }
.site-nav > a.active { color: var(--navy); font-weight: 600; }
.site-nav .nav-cta { background: var(--gold); color: var(--navy); padding: 10px 24px; border-radius: 50px; font-weight: 600; }
.site-nav .nav-cta::after { display: none; }
.site-nav .nav-cta:hover { background: #ffb838; color: var(--navy); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 560px;
  display: flex;
  align-items: center;
  background: url('/img/banner.jpg') center center / cover no-repeat;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(100deg, rgba(7, 20, 39, .88) 0%, rgba(11, 31, 58, .62) 45%, rgba(11, 31, 58, .25) 100%);
}
.hero-content { position: relative; z-index: 2; max-width: 720px; padding: 90px 0; color: var(--white); }
.hero-tag {
  display: inline-block; background: rgba(245, 166, 35, .16); border: 1px solid var(--gold);
  color: var(--gold); font-family: 'Prompt', sans-serif; font-size: 13.5px; font-weight: 500;
  padding: 6px 18px; border-radius: 50px; margin-bottom: 22px; letter-spacing: .5px;
}
.hero h1 { color: var(--white); font-size: clamp(30px, 4.6vw, 50px); font-weight: 700; margin-bottom: 18px; }
.hero h1 em { color: var(--gold); font-style: normal; }
.hero p { font-size: 17.5px; color: rgba(255, 255, 255, .88); margin-bottom: 34px; max-width: 600px; }
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }

/* ---------- Section base ---------- */
.section { padding: 84px 0; }
.section-soft { background: var(--bg-soft); }
.section-head { text-align: center; max-width: 760px; margin: 0 auto 52px; }
.section-head .kicker {
  display: inline-block; color: var(--gold-dark); font-family: 'Prompt', sans-serif;
  font-weight: 600; letter-spacing: 2.5px; font-size: 13px; text-transform: uppercase; margin-bottom: 10px;
}
.section-head h2 { font-size: clamp(26px, 3.4vw, 38px); margin-bottom: 14px; }
.section-head p { color: var(--muted); font-size: 16.5px; }
.section-head.left { text-align: left; margin: 0 0 40px; }

/* ---------- Stats ---------- */
.stats-band { background: var(--navy); color: var(--white); padding: 46px 0; }
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 28px; text-align: center; }
.stat-num { font-family: 'Prompt', sans-serif; font-size: clamp(28px, 3.2vw, 42px); font-weight: 700; color: var(--gold); }
.stat-num small { font-size: .5em; font-weight: 500; }
.stat-label { font-size: 14.5px; color: rgba(255, 255, 255, .8); margin-top: 4px; }

/* ---------- About split ---------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.split-img { position: relative; }
.split-img img { border-radius: var(--radius); box-shadow: var(--shadow); width: 100%; }
.split-body h2 { font-size: clamp(24px, 3vw, 34px); margin-bottom: 18px; }
.split-body p { color: var(--muted); margin-bottom: 16px; }
.check-list { list-style: none; margin: 22px 0 30px; }
.check-list li { padding: 7px 0 7px 34px; position: relative; color: var(--ink); }
.check-list li::before {
  content: "✓"; position: absolute; left: 0; top: 7px; width: 22px; height: 22px;
  background: rgba(245, 166, 35, .18); color: var(--gold-dark); border-radius: 50%;
  display: flex; align-items: center; justify-content: center; font-size: 13px; font-weight: 700;
}

/* ---------- Product cards ---------- */
.cards-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.card {
  background: var(--white); border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-sm); border: 1px solid var(--line);
  display: flex; flex-direction: column; transition: transform .25s, box-shadow .25s;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow); }
.card-img { aspect-ratio: 4 / 3; overflow: hidden; background: var(--bg-soft); }
.card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform .4s; }
.card:hover .card-img img { transform: scale(1.05); }
.card-body { padding: 24px 26px 28px; flex: 1; display: flex; flex-direction: column; }
.card-body h3 { font-size: 20px; margin-bottom: 10px; }
.card-body h3 a { color: var(--navy); }
.card-body h3 a:hover { color: var(--gold-dark); }
.card-body p { color: var(--muted); font-size: 14.8px; flex: 1; }
.card-link {
  margin-top: 18px; font-family: 'Prompt', sans-serif; font-weight: 600; font-size: 14.5px;
  color: var(--gold-dark); display: inline-flex; align-items: center; gap: 6px;
}
.card-link:hover { gap: 10px; color: var(--gold); }

/* ---------- Feature tiles ---------- */
.tiles-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 26px; }
.tile { background: var(--white); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-sm); }
.tile img { width: 100%; aspect-ratio: 3 / 2; object-fit: cover; }
.tile-body { padding: 18px 20px 22px; }
.tile-body h3 { font-size: 17px; margin-bottom: 6px; }
.tile-body p { font-size: 14px; color: var(--muted); }

/* ---------- Certificates ---------- */
.certs-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; max-width: 900px; margin: 0 auto; }
.cert { background: var(--white); border-radius: var(--radius); box-shadow: var(--shadow-sm); padding: 18px; text-align: center; border: 1px solid var(--line); }
.cert img { border-radius: 6px; aspect-ratio: 700 / 989; object-fit: cover; width: 100%; }
.cert h3 { font-size: 16px; margin-top: 14px; }

/* ---------- Page hero (inner pages) ---------- */
.page-hero {
  background: linear-gradient(105deg, rgba(7, 20, 39, .92), rgba(18, 44, 79, .82)), url('/img/banner.jpg') center / cover no-repeat;
  padding: 74px 0 66px; color: var(--white); text-align: center;
}
.page-hero h1 { color: var(--white); font-size: clamp(28px, 4vw, 42px); margin-bottom: 10px; }
.breadcrumb { font-size: 14px; color: rgba(255, 255, 255, .75); }
.breadcrumb a { color: var(--gold); }
.breadcrumb span { margin: 0 8px; color: rgba(255, 255, 255, .4); }

/* ---------- Product detail ---------- */
.product-top { display: grid; grid-template-columns: 460px 1fr; gap: 54px; align-items: start; }
.product-top .product-img { border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); border: 1px solid var(--line); background: var(--white); }
.product-top .product-img img { width: 100%; }
.product-info h1 { font-size: clamp(25px, 3vw, 34px); margin-bottom: 8px; }
.product-info .sub { color: var(--gold-dark); font-family: 'Prompt', sans-serif; font-weight: 500; margin-bottom: 18px; }
.product-info p { color: var(--muted); margin-bottom: 14px; }
.spec-list { list-style: none; margin: 20px 0 28px; display: grid; grid-template-columns: 1fr 1fr; gap: 10px 22px; }
.spec-list li {
  background: var(--bg-soft); border-radius: 8px; padding: 10px 16px;
  font-size: 14.5px; color: var(--ink); border-left: 3px solid var(--gold);
}
.product-section { margin-top: 56px; }
.product-section h2 { font-size: 24px; margin-bottom: 16px; padding-left: 16px; border-left: 4px solid var(--gold); }
.product-section p, .product-section li { color: var(--muted); }
.product-section ul, .product-section ol { padding-left: 24px; margin: 10px 0 16px; }
.product-section li { margin-bottom: 8px; }

/* ---------- FAQ ---------- */
.faq-list { max-width: 860px; margin: 0 auto; }
.faq-item {
  background: var(--white); border: 1px solid var(--line); border-radius: var(--radius);
  margin-bottom: 16px; overflow: hidden; box-shadow: var(--shadow-sm);
}
.faq-item summary {
  cursor: pointer; padding: 20px 56px 20px 24px; font-family: 'Prompt', sans-serif;
  font-weight: 600; font-size: 17px; color: var(--navy); position: relative; list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+"; position: absolute; right: 22px; top: 50%; transform: translateY(-50%);
  width: 28px; height: 28px; background: rgba(245, 166, 35, .15); color: var(--gold-dark);
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  font-weight: 700; transition: transform .25s;
}
.faq-item[open] summary::after { content: "−"; }
.faq-item .faq-body { padding: 0 24px 24px; color: var(--muted); }
.faq-item .faq-body p { margin-bottom: 12px; }
.faq-item .faq-body ul, .faq-item .faq-body ol { padding-left: 22px; margin-bottom: 12px; }
.faq-item .faq-body li { margin-bottom: 6px; }
.faq-item .faq-body strong { color: var(--ink); }

/* ---------- Contact ---------- */
.contact-wrap { display: grid; grid-template-columns: 1fr 1.15fr; gap: 56px; align-items: start; }
.contact-info h2 { font-size: 28px; margin-bottom: 14px; }
.contact-info p { color: var(--muted); margin-bottom: 26px; }
.info-line { display: flex; gap: 14px; padding: 14px 0; border-bottom: 1px dashed var(--line); }
.info-line .ico {
  flex: 0 0 42px; height: 42px; background: rgba(245, 166, 35, .15); border-radius: 10px;
  display: flex; align-items: center; justify-content: center; font-size: 19px;
}
.info-line strong { display: block; font-family: 'Prompt', sans-serif; font-size: 15px; color: var(--navy); }
.info-line span { font-size: 14.5px; color: var(--muted); }

.form-card { background: var(--white); border-radius: var(--radius); box-shadow: var(--shadow); padding: 38px 40px; border: 1px solid var(--line); }
.form-card h2 { font-size: 24px; margin-bottom: 6px; }
.form-card .form-sub { color: var(--muted); font-size: 14.5px; margin-bottom: 24px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.form-group { margin-bottom: 18px; }
.form-group label { display: block; font-family: 'Prompt', sans-serif; font-weight: 500; font-size: 14.5px; color: var(--navy); margin-bottom: 7px; }
.form-group label em { color: #d93025; font-style: normal; }
.form-group input, .form-group textarea {
  width: 100%; padding: 13px 16px; border: 1.5px solid var(--line); border-radius: 8px;
  font-family: 'Sarabun', sans-serif; font-size: 15px; color: var(--ink);
  background: var(--bg-soft); transition: border-color .2s, background .2s;
}
.form-group input:focus, .form-group textarea:focus {
  outline: none; border-color: var(--gold); background: var(--white);
}
.form-group textarea { resize: vertical; min-height: 130px; }
.form-note { font-size: 13px; color: var(--muted); margin-top: 12px; }
.form-status { display: none; margin-top: 16px; padding: 13px 18px; border-radius: 8px; font-size: 14.5px; }
.form-status.ok { display: block; background: #e8f6ec; color: #1c7c3c; border: 1px solid #bfe5cc; }
.form-status.err, .form-status.error { display: block; background: #fdecec; color: #c0392b; border: 1px solid #f3c4c0; }

/* Contact page — form (left) & info side (right) */
.contact-form { background: var(--white); border-radius: var(--radius); box-shadow: var(--shadow); padding: 38px 40px; border: 1px solid var(--line); }
.form-field { margin-bottom: 18px; }
.form-field label { display: block; font-family: 'Prompt', sans-serif; font-weight: 500; font-size: 14.5px; color: var(--navy); margin-bottom: 7px; }
.form-field .req { color: #d93025; }
.form-field input, .form-field select, .form-field textarea {
  width: 100%; padding: 13px 16px; border: 1.5px solid var(--line); border-radius: 8px;
  font-family: 'Sarabun', sans-serif; font-size: 15px; color: var(--ink);
  background: var(--bg-soft); transition: border-color .2s, background .2s;
}
.form-field input:focus, .form-field select:focus, .form-field textarea:focus {
  outline: none; border-color: var(--gold); background: var(--white);
}
.form-field textarea { resize: vertical; min-height: 130px; }
.contact-side .side-item {
  background: var(--bg-soft); border-radius: var(--radius); padding: 24px 26px;
  margin-bottom: 18px; border-left: 4px solid var(--gold);
}
.side-item h3 { font-size: 17px; margin-bottom: 8px; }
.side-item p { color: var(--muted); font-size: 14.5px; }

/* ---------- CTA band ---------- */
.cta-band { background: linear-gradient(100deg, var(--navy) 0%, var(--navy-3) 100%); color: var(--white); padding: 66px 0; }
.cta-inner { display: flex; align-items: center; justify-content: space-between; gap: 30px; flex-wrap: wrap; }
.cta-inner h2 { color: var(--white); font-size: clamp(22px, 3vw, 32px); margin-bottom: 8px; }
.cta-inner p { color: rgba(255, 255, 255, .8); font-size: 16px; max-width: 640px; }

/* ---------- Footer ---------- */
.site-footer { background: #081527; color: rgba(255, 255, 255, .72); font-size: 14.5px; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr; gap: 46px; padding: 64px 0 48px; }
.footer-grid h3 { color: var(--white); font-size: 17px; margin-bottom: 18px; position: relative; padding-bottom: 10px; }
.footer-grid h3::after { content: ""; position: absolute; left: 0; bottom: 0; width: 34px; height: 2.5px; background: var(--gold); border-radius: 2px; }
.footer-about img { width: 52px; margin-bottom: 14px; border-radius: 4px; }
.footer-about p { margin-bottom: 14px; }
.footer-links ul { list-style: none; }
.footer-links li { margin-bottom: 10px; }
.footer-links a { color: rgba(255, 255, 255, .72); }
.footer-links a:hover { color: var(--gold); }
.footer-bottom { border-top: 1px solid rgba(255, 255, 255, .1); padding: 20px 0; text-align: center; font-size: 13.5px; color: rgba(255, 255, 255, .5); }

/* ---------- Related products ---------- */
.related-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .cards-grid { grid-template-columns: repeat(2, 1fr); }
  .tiles-grid { grid-template-columns: repeat(2, 1fr); }
  .product-top { grid-template-columns: 1fr; gap: 36px; }
  .product-top .product-img { max-width: 560px; }
  .related-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .section { padding: 60px 0; }
  .nav-burger { display: block; }
  .nav-toggle:checked ~ .nav-burger span { background: transparent; }
  .nav-toggle:checked ~ .nav-burger span::before { transform: rotate(45deg); top: 0; }
  .nav-toggle:checked ~ .nav-burger span::after { transform: rotate(-45deg); top: 0; }
  .site-nav {
    position: absolute; top: 100%; left: 0; right: 0; background: var(--white);
    flex-direction: column; align-items: stretch; gap: 0; padding: 10px 20px 20px;
    box-shadow: 0 14px 24px rgba(11, 31, 58, .12); display: none;
  }
  .nav-toggle:checked ~ .site-nav { display: flex; }
  .site-nav > a { padding: 13px 4px; border-bottom: 1px solid var(--line); }
  .site-nav > a::after { display: none; }
  .site-nav .nav-cta { margin-top: 14px; text-align: center; border-bottom: none; }
  .split, .contact-wrap { grid-template-columns: 1fr; gap: 36px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .form-row { grid-template-columns: 1fr; }
  .hero { min-height: 480px; }
  .certs-grid { grid-template-columns: 1fr; max-width: 420px; }
  .cta-inner { flex-direction: column; text-align: center; }
}

@media (max-width: 520px) {
  .cards-grid, .tiles-grid, .related-grid { grid-template-columns: 1fr; }
  .spec-list { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 34px; }
}