/* Design tokens */
:root {
  --bg: #1a1a2e;
  --bg-card: #252540;
  --bg-card-hover: #2e2e55;
  --accent: #e8650a;
  --accent-hover: #d45a00;
  --text: #ffffff;
  --text-muted: #aaaaaa;
  --border: rgba(255,255,255,0.08);
  --font-zh: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
  --font-en: 'Inter', sans-serif;
  --radius: 6px;
  --transition: 0.2s ease;
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { background: var(--bg); color: var(--text); font-family: var(--font-zh); line-height: 1.6; }
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { cursor: pointer; border: none; background: none; font: inherit; }

/* Google Font (English pages) */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap');

/* ===== NAVIGATION ===== */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 5%;
  height: 64px;
  transition: background var(--transition), backdrop-filter var(--transition);
}
.nav.scrolled {
  background: rgba(26,26,46,0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.nav-logo { display: flex; align-items: center; gap: 10px; }
.nav-logo img { height: 36px; }
.nav-logo-text { font-size: 16px; font-weight: 700; letter-spacing: 1px; color: var(--text); }
.nav-links { display: flex; align-items: center; gap: 32px; }
.nav-links a { font-size: 14px; color: var(--text-muted); transition: color var(--transition); }
.nav-links a:hover, .nav-links a.active { color: var(--text); }
.nav-lang {
  font-size: 12px; font-weight: 600; color: var(--accent);
  border: 1px solid var(--accent); padding: 4px 10px; border-radius: 3px;
  transition: all var(--transition);
}
.nav-lang:hover { background: var(--accent); color: #fff; }
.nav-menu-btn { display: none; flex-direction: column; gap: 5px; padding: 4px; }
.nav-menu-btn span { display: block; width: 22px; height: 2px; background: var(--text); border-radius: 2px; }
.nav-mobile { display: none; position: fixed; inset: 64px 0 0; background: var(--bg); z-index: 99;
  flex-direction: column; align-items: center; justify-content: center; gap: 32px; }
.nav-mobile.open { display: flex; }
.nav-mobile a { font-size: 20px; color: var(--text-muted); }

/* ===== HERO ===== */
.hero {
  position: relative; min-height: 100vh;
  display: flex; align-items: center;
  background-size: cover; background-position: center; background-repeat: no-repeat;
}
.hero::after {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(26,26,46,0.85) 0%, rgba(26,26,46,0.5) 60%, transparent 100%);
}
.hero-content {
  position: relative; z-index: 1;
  max-width: 600px; padding: 0 5%;
}
.hero-tag { font-size: 12px; letter-spacing: 4px; color: var(--accent); margin-bottom: 16px; text-transform: uppercase; }
.hero-title { font-size: clamp(32px, 5vw, 56px); font-weight: 700; line-height: 1.2; margin-bottom: 16px; }
.hero-subtitle { font-size: 16px; color: var(--text-muted); margin-bottom: 32px; }
.btn-primary {
  display: inline-block; background: var(--accent); color: #fff;
  padding: 14px 32px; border-radius: var(--radius); font-size: 15px; font-weight: 600;
  transition: background var(--transition), transform var(--transition);
}
.btn-primary:hover { background: var(--accent-hover); transform: translateY(-1px); }
.btn-secondary {
  display: inline-block; border: 1px solid var(--accent); color: var(--accent);
  padding: 13px 31px; border-radius: var(--radius); font-size: 15px;
  transition: all var(--transition); margin-left: 12px;
}
.btn-secondary:hover { background: var(--accent); color: #fff; }

/* ===== STATS BAR ===== */
.stats { padding: 48px 5%; }
.stats-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px;
  max-width: 900px; margin: 0 auto;
}
.stat-card {
  background: var(--bg-card); border-radius: var(--radius);
  padding: 24px; text-align: center;
  border: 1px solid var(--border);
}
.stat-number { font-size: 32px; font-weight: 700; color: var(--accent); }
.stat-label { font-size: 13px; color: var(--text-muted); margin-top: 4px; }

/* ===== SECTION COMMON ===== */
.section { padding: 80px 5%; }
.section-header { text-align: center; margin-bottom: 48px; }
.section-tag { font-size: 11px; letter-spacing: 4px; color: var(--accent); text-transform: uppercase; margin-bottom: 8px; }
.section-title { font-size: clamp(24px, 3vw, 36px); font-weight: 700; }
.section-subtitle { font-size: 15px; color: var(--text-muted); margin-top: 8px; }

/* ===== PRODUCT GRID (homepage) ===== */
.product-grid-home {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px;
  max-width: 1200px; margin: 0 auto;
}
.product-tile {
  position: relative; overflow: hidden; border-radius: var(--radius);
  aspect-ratio: 1; background: var(--bg-card); cursor: pointer;
}
.product-tile img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.4s ease; }
.product-tile:hover img { transform: scale(1.05); }
.product-tile-label {
  position: absolute; inset: 0;
  display: flex; align-items: flex-end; padding: 16px;
  background: linear-gradient(to top, rgba(0,0,0,0.7) 0%, transparent 50%);
}
.product-tile-label span { font-size: 15px; font-weight: 600; }

/* ===== FEATURES (why choose us) ===== */
.features-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
  max-width: 1000px; margin: 0 auto;
}
.feature-card {
  background: var(--bg-card); border-radius: var(--radius);
  padding: 32px 24px; text-align: center; border: 1px solid var(--border);
  transition: border-color var(--transition), transform var(--transition);
}
.feature-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.feature-icon { font-size: 36px; margin-bottom: 12px; }
.feature-name { font-size: 16px; font-weight: 600; margin-bottom: 6px; }
.feature-name-en { font-size: 11px; color: var(--text-muted); letter-spacing: 2px; margin-bottom: 8px; }
.feature-desc { font-size: 13px; color: var(--text-muted); }

/* ===== CERT BANNER ===== */
.cert-banner { padding: 0 5% 80px; }
.cert-banner img { width: 100%; max-width: 1200px; margin: 0 auto; border-radius: var(--radius); }

/* ===== CTA SECTION ===== */
.cta-section {
  padding: 80px 5%; text-align: center;
  background: linear-gradient(135deg, var(--bg-card), var(--bg));
  border-top: 1px solid var(--border); border-bottom: 1px solid var(--border);
}
.cta-title { font-size: clamp(24px, 3vw, 40px); font-weight: 700; margin-bottom: 12px; }
.cta-subtitle { font-size: 16px; color: var(--text-muted); margin-bottom: 32px; }

/* ===== FOOTER ===== */
footer {
  padding: 48px 5% 24px;
  border-top: 1px solid var(--border);
}
.footer-grid {
  display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 40px;
  max-width: 1200px; margin: 0 auto 40px;
}
.footer-brand-name { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.footer-brand-sub { font-size: 12px; color: var(--text-muted); letter-spacing: 2px; margin-bottom: 12px; }
.footer-brand-desc { font-size: 13px; color: var(--text-muted); line-height: 1.7; }
.footer-col-title { font-size: 12px; font-weight: 600; color: var(--accent); letter-spacing: 2px; text-transform: uppercase; margin-bottom: 16px; }
.footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 8px; }
.footer-col ul li a { font-size: 14px; color: var(--text-muted); transition: color var(--transition); }
.footer-col ul li a:hover { color: var(--text); }
.footer-contact-item { font-size: 14px; color: var(--text-muted); margin-bottom: 8px; }
.footer-bottom {
  border-top: 1px solid var(--border); padding-top: 24px;
  text-align: center; font-size: 12px; color: var(--text-muted);
}

/* ===== PRODUCT CATALOG PAGE ===== */
.page-hero {
  padding: 120px 5% 48px;
  background: linear-gradient(135deg, var(--bg-card), var(--bg));
  border-bottom: 1px solid var(--border);
}
.page-hero-title { font-size: clamp(28px, 4vw, 48px); font-weight: 700; margin-bottom: 8px; }
.page-hero-sub { font-size: 14px; color: var(--text-muted); letter-spacing: 3px; }

.tabs { display: flex; gap: 8px; flex-wrap: wrap; padding: 32px 5% 0; border-bottom: 1px solid var(--border); }
.tab-btn {
  padding: 10px 20px; font-size: 14px; color: var(--text-muted);
  border-bottom: 2px solid transparent; transition: all var(--transition);
}
.tab-btn:hover { color: var(--text); }
.tab-btn.active { color: var(--accent); border-bottom-color: var(--accent); }

.products-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px; padding: 40px 5%;
  max-width: 1400px; margin: 0 auto;
}
.product-card {
  background: var(--bg-card); border-radius: var(--radius);
  overflow: hidden; border: 1px solid var(--border);
  transition: border-color var(--transition), transform var(--transition);
  cursor: pointer;
}
.product-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.product-card img { width: 100%; aspect-ratio: 4/3; object-fit: cover; }
.product-card-body { padding: 16px; }
.product-code { font-size: 18px; font-weight: 700; color: var(--accent); }
.product-name { font-size: 15px; font-weight: 600; margin: 4px 0; }
.product-spec { font-size: 13px; color: var(--text-muted); margin-bottom: 12px; }
.btn-inquire {
  width: 100%; padding: 10px; background: var(--accent); color: #fff;
  border-radius: var(--radius); font-size: 14px; font-weight: 600;
  transition: background var(--transition);
}
.btn-inquire:hover { background: var(--accent-hover); }

/* ===== MODAL ===== */
.modal-backdrop {
  display: none; position: fixed; inset: 0; z-index: 200;
  background: rgba(0,0,0,0.7); backdrop-filter: blur(4px);
  align-items: center; justify-content: center; padding: 20px;
}
.modal-backdrop.open { display: flex; }
.modal {
  background: var(--bg-card); border-radius: var(--radius);
  max-width: 600px; width: 100%; padding: 32px;
  position: relative; border: 1px solid var(--border);
}
.modal-close {
  position: absolute; top: 16px; right: 16px;
  font-size: 24px; color: var(--text-muted); line-height: 1;
}
.modal-close:hover { color: var(--text); }
.modal-img { width: 100%; border-radius: 4px; margin-bottom: 16px; }
.modal-code { font-size: 22px; font-weight: 700; color: var(--accent); }
.modal-name { font-size: 18px; font-weight: 600; margin: 4px 0 8px; }
.modal-spec { font-size: 14px; color: var(--text-muted); margin-bottom: 16px; }

/* ===== ABOUT PAGE ===== */
.about-intro { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; padding: 100px 5% 60px; }
.about-text h2 { font-size: clamp(24px, 3vw, 36px); font-weight: 700; margin-bottom: 16px; }
.about-text p { font-size: 15px; color: var(--text-muted); line-height: 1.8; margin-bottom: 12px; }
.about-img { border-radius: var(--radius); overflow: hidden; }
.about-img img { width: 100%; }
.factory-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 32px; }
.factory-grid img { border-radius: var(--radius); width: 100%; aspect-ratio: 16/9; object-fit: cover; }
.process-img { padding: 0 5% 80px; }
.process-img img { width: 100%; border-radius: var(--radius); }

/* ===== CONTACT PAGE ===== */
.contact-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; padding: 100px 5% 80px; max-width: 1200px; margin: 0 auto; }
.contact-info h2 { font-size: 28px; font-weight: 700; margin-bottom: 8px; }
.contact-info p { font-size: 15px; color: var(--text-muted); margin-bottom: 32px; }
.contact-item { display: flex; gap: 12px; margin-bottom: 20px; }
.contact-item-icon { font-size: 20px; flex-shrink: 0; margin-top: 2px; }
.contact-item-label { font-size: 12px; color: var(--accent); font-weight: 600; letter-spacing: 1px; margin-bottom: 2px; }
.contact-item-value { font-size: 15px; }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; font-size: 13px; color: var(--text-muted); margin-bottom: 6px; }
.form-group label .required { color: var(--accent); margin-left: 2px; }
.form-control {
  width: 100%; padding: 12px 16px; background: var(--bg-card);
  border: 1px solid var(--border); border-radius: var(--radius);
  color: var(--text); font-size: 14px; font-family: inherit;
  transition: border-color var(--transition);
}
.form-control:focus { outline: none; border-color: var(--accent); }
.form-control.error { border-color: #e85c0a; }
.form-error { font-size: 12px; color: #e85c0a; margin-top: 4px; display: none; }
.form-error.visible { display: block; }
textarea.form-control { resize: vertical; min-height: 100px; }
.form-success {
  display: none; padding: 16px; background: rgba(232,101,10,0.1);
  border: 1px solid var(--accent); border-radius: var(--radius);
  text-align: center; font-size: 15px;
}
.form-success.visible { display: block; }

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-menu-btn { display: flex; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .product-grid-home { grid-template-columns: repeat(2, 1fr); }
  .features-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .about-intro { grid-template-columns: 1fr; }
  .contact-layout { grid-template-columns: 1fr; }
  .factory-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .product-grid-home { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
}