/* ═══════════════════════════════════════
   SINOTRUCK.WORK — Industrial B2B Stylesheet
   Dark industrial theme with safety-orange accents
═══════════════════════════════════════ */

:root {
  --ink: #0d1117;
  --ink-2: #161b22;
  --ink-3: #1f2630;
  --line: #2d3748;
  --text: #c9d1d9;
  --text-dim: #8b949e;
  --white: #f0f6fc;
  --orange: #f0883e;
  --orange-2: #ff9f5a;
  --orange-dark: #c96a24;
  --green: #3fb950;
  --maxw: 1200px;
  --radius: 12px;
  --shadow: 0 8px 30px rgba(0,0,0,.45);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--ink);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

h1, h2, h3, h4, h5 { color: var(--white); line-height: 1.25; }

a { color: var(--orange-2); text-decoration: none; }

/* ─────────── Buttons ─────────── */
.btn {
  display: inline-block;
  padding: 14px 32px;
  border-radius: 8px;
  font-weight: 700;
  font-size: 15px;
  letter-spacing: .3px;
  transition: all .2s ease;
  border: 2px solid transparent;
  cursor: pointer;
}
.btn-primary { background: var(--orange); color: #1a1108; }
.btn-primary:hover { background: var(--orange-2); transform: translateY(-2px); box-shadow: 0 6px 20px rgba(240,136,62,.35); }
.btn-ghost { border-color: rgba(240,246,252,.4); color: var(--white); }
.btn-ghost:hover { border-color: var(--orange-2); color: var(--orange-2); }
.btn-block { width: 100%; }

/* ─────────── Header ─────────── */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(13,17,23,.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(45,55,72,.6);
  transition: background .3s ease;
}
.site-header.scrolled { background: rgba(13,17,23,.97); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 72px; }
.brand { display: flex; align-items: center; gap: 10px; }
.brand-logo { width: 38px; height: 38px; }
.brand-text { font-size: 20px; font-weight: 800; color: var(--white); letter-spacing: .5px; }
.brand-dot { color: var(--orange); }

.main-nav { display: flex; align-items: center; gap: 28px; }
.main-nav a { color: var(--text); font-size: 15px; font-weight: 500; transition: color .2s; }
.main-nav a:hover { color: var(--orange-2); }
.main-nav .nav-cta {
  background: var(--orange); color: #1a1108;
  padding: 9px 18px; border-radius: 6px; font-weight: 700;
}
.main-nav .nav-cta:hover { background: var(--orange-2); color: #1a1108; }

.nav-toggle { display: none; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav-toggle span { display: block; width: 24px; height: 2px; background: var(--white); margin: 5px 0; transition: .3s; }

/* ─────────── Hero ─────────── */
.hero { position: relative; min-height: 92vh; display: flex; align-items: center; overflow: hidden; }
.hero-bg { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.hero-overlay {
  position: absolute; inset: 0;
  background: linear-gradient(100deg, rgba(10,14,19,.92) 20%, rgba(10,14,19,.55) 60%, rgba(10,14,19,.25));
}
.hero-content { position: relative; z-index: 2; padding: 160px 24px 90px; }
.hero-kicker {
  display: inline-block; color: var(--orange-2);
  font-weight: 700; letter-spacing: 1.5px; text-transform: uppercase; font-size: 13px;
  border: 1px solid rgba(240,136,62,.4); border-radius: 30px; padding: 6px 16px; margin-bottom: 22px;
  background: rgba(240,136,62,.08);
}
.hero h1 { font-size: clamp(32px, 5vw, 56px); font-weight: 900; margin-bottom: 20px; }
.hero h1 span { color: var(--orange-2); }
.hero-sub { max-width: 620px; font-size: 17px; color: var(--text-dim); margin-bottom: 32px; }
.hero-cta { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 56px; }

.hero-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; max-width: 760px; }
.stat {
  background: rgba(22,27,34,.7); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px 14px; text-align: center; backdrop-filter: blur(6px);
}
.stat strong { display: block; font-size: 28px; color: var(--orange-2); font-weight: 900; }
.stat span { font-size: 13px; color: var(--text-dim); }

/* ─────────── Sections ─────────── */
.section { padding: 96px 0; }
.section-head { text-align: center; max-width: 700px; margin: 0 auto 56px; }
.section-kicker { color: var(--orange); font-weight: 700; letter-spacing: 2px; text-transform: uppercase; font-size: 13px; margin-bottom: 10px; }
.section-head h2 { font-size: clamp(28px, 4vw, 40px); font-weight: 800; margin-bottom: 14px; }
.section-sub { color: var(--text-dim); font-size: 16px; }

/* ─────────── Products ─────────── */
.product-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.product-card {
  background: var(--ink-2); border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; transition: transform .25s ease, box-shadow .25s ease;
}
.product-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); }
.product-img { width: 100%; height: 220px; object-fit: cover; }
.product-body { padding: 26px; }
.product-body h3 { font-size: 21px; margin-bottom: 10px; }
.product-body p { color: var(--text-dim); font-size: 15px; margin-bottom: 16px; }
.product-tags { list-style: none; display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.product-tags li {
  background: rgba(240,136,62,.12); color: var(--orange-2);
  border: 1px solid rgba(240,136,62,.3); border-radius: 20px;
  padding: 4px 12px; font-size: 12.5px; font-weight: 600;
}
.link-more { font-weight: 700; font-size: 14.5px; }

/* ─────────── Process ─────────── */
.process { background: var(--ink-2); }
.process-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; margin-bottom: 70px; }
.process-step {
  background: var(--ink-3); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 18px; position: relative;
}
.step-num {
  position: absolute; top: 14px; right: 16px;
  font-size: 30px; font-weight: 900; color: rgba(240,136,62,.18);
}
.process-step img { width: 100%; height: 130px; object-fit: cover; border-radius: 8px; margin-bottom: 14px; }
.process-step h4 { font-size: 15.5px; margin-bottom: 6px; }
.process-step p { font-size: 13px; color: var(--text-dim); }

.video-block { max-width: 760px; margin: 0 auto; text-align: center; }
.video-block h3 { margin-bottom: 20px; font-size: 24px; }
.video-block video { width: 100%; border-radius: var(--radius); border: 1px solid var(--line); background: #000; }

/* ─────────── Why Us ─────────── */
.why-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }
.why-item {
  background: var(--ink-2); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; text-align: center; transition: transform .2s;
}
.why-item:hover { transform: translateY(-4px); }
.why-item img { width: 100%; height: 150px; object-fit: cover; border-radius: 8px; margin-bottom: 16px; }
.why-item h4 { font-size: 17px; margin-bottom: 8px; }
.why-item p { font-size: 14px; color: var(--text-dim); }

/* ─────────── Markets ─────────── */
.markets { background: var(--ink-2); }
.market-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.market-card {
  background: var(--ink-3); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden;
}
.market-card img { width: 100%; height: 200px; object-fit: cover; }
.market-card h3 { font-size: 22px; padding: 22px 24px 6px; }
.market-card p { color: var(--text-dim); font-size: 15px; padding: 0 24px 12px; }
.market-card ul { list-style: none; padding: 0 24px 24px; }
.market-card li { font-size: 13.5px; color: var(--text); padding: 4px 0 4px 18px; position: relative; }
.market-card li::before { content: "▸"; position: absolute; left: 0; color: var(--orange); }

/* ─────────── Quality ─────────── */
.quality-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 26px; }
.quality-item {
  background: var(--ink-2); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; text-align: center;
}
.quality-item img { width: 100%; height: 160px; object-fit: cover; border-radius: 8px; margin-bottom: 16px; }
.quality-item h4 { font-size: 17px; margin-bottom: 8px; }
.quality-item p { font-size: 14px; color: var(--text-dim); }

/* ─────────── Contact ─────────── */
.contact { background: linear-gradient(180deg, var(--ink) 0%, var(--ink-2) 100%); }
.contact-wrap { display: grid; grid-template-columns: 1fr 1.1fr; gap: 56px; align-items: start; }
.contact-info h2 { font-size: 34px; margin-bottom: 14px; }
.contact-info > p { color: var(--text-dim); margin-bottom: 24px; }
.contact-lines { margin-bottom: 24px; }
.contact-lines p { padding: 8px 0; border-bottom: 1px solid var(--line); }
.contact-lines strong { color: var(--white); }
.contact-note {
  background: rgba(240,136,62,.08); border: 1px solid rgba(240,136,62,.3);
  border-radius: var(--radius); padding: 18px; font-size: 14.5px; color: var(--text);
}

.quote-form {
  background: var(--ink-2); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 32px;
}
.form-row { margin-bottom: 18px; }
.form-row label { display: block; font-size: 13.5px; font-weight: 600; color: var(--text); margin-bottom: 6px; }
.form-row input, .form-row select, .form-row textarea {
  width: 100%; background: var(--ink-3); border: 1px solid var(--line);
  border-radius: 8px; color: var(--white); padding: 12px 14px; font-size: 15px;
  font-family: inherit; transition: border-color .2s;
}
.form-row input:focus, .form-row select:focus, .form-row textarea:focus {
  outline: none; border-color: var(--orange);
}
.form-row textarea { resize: vertical; }
.form-hint { margin-top: 14px; font-size: 13px; color: var(--text-dim); text-align: center; }
.form-hint.success { color: var(--green); }
.form-hint.error { color: #f85149; }

/* ─────────── Footer ─────────── */
.site-footer { background: #0a0d12; border-top: 1px solid var(--line); }
.footer-inner { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.2fr; gap: 40px; padding: 56px 24px; }
.footer-brand img { margin-bottom: 12px; }
.footer-brand p { color: var(--text-dim); font-size: 14px; max-width: 300px; }
.footer-links h5, .footer-contact h5 { font-size: 15px; margin-bottom: 14px; color: var(--white); }
.footer-links a { display: block; color: var(--text-dim); font-size: 14px; padding: 4px 0; }
.footer-links a:hover { color: var(--orange-2); }
.footer-contact p { color: var(--text-dim); font-size: 14px; padding: 3px 0; }
.footer-bottom { border-top: 1px solid var(--line); padding: 20px 0; }
.footer-bottom p { font-size: 13px; color: var(--text-dim); text-align: center; }

/* ─────────── Responsive ─────────── */
@media (max-width: 992px) {
  .product-grid, .why-grid, .market-grid, .quality-grid { grid-template-columns: repeat(2, 1fr); }
  .process-grid { grid-template-columns: repeat(2, 1fr); }
  .contact-wrap { grid-template-columns: 1fr; gap: 40px; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .section { padding: 70px 0; }
  .product-grid, .why-grid, .market-grid, .quality-grid { grid-template-columns: 1fr; }
  .process-grid { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .hero { min-height: auto; }
  .hero-content { padding: 130px 20px 60px; }
  .hero-cta { flex-direction: column; }
  .btn { width: 100%; text-align: center; }

  .main-nav {
    display: none; position: absolute; top: 72px; left: 0; right: 0;
    background: var(--ink-2); border-bottom: 1px solid var(--line);
    flex-direction: column; gap: 0; padding: 12px 24px 20px;
  }
  .main-nav.open { display: flex; }
  .main-nav a { padding: 12px 0; width: 100%; }
  .main-nav .nav-cta { text-align: center; }
  .nav-toggle { display: block; }
  .footer-inner { grid-template-columns: 1fr; gap: 28px; }
}