:root {
  --color-primary: #1f3a5f;
  --color-primary-dark: #16293f;
  --color-primary-light: #2c4f7c;
  --color-accent: #c8923a;
  --color-accent-dark: #b07d28;
  --color-text: #2a2f36;
  --color-text-soft: #5c6670;
  --color-bg: #ffffff;
  --color-bg-soft: #f5f7fa;
  --color-bg-dark: #16293f;
  --color-border: #e3e8ee;
  --color-success: #2e8b57;
  --shadow-sm: 0 2px 10px rgba(22, 41, 63, 0.06);
  --shadow-md: 0 10px 30px rgba(22, 41, 63, 0.10);
  --shadow-lg: 0 20px 50px rgba(22, 41, 63, 0.16);
  --radius: 10px;
  --radius-lg: 18px;
  --maxw: 1200px;
  --font: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, "Hiragino Sans GB", sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: 50px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  border: 1.5px solid transparent;
  transition: all 0.25s ease;
  white-space: nowrap;
}
.btn-primary { background: var(--color-accent); color: #fff; }
.btn-primary:hover { background: var(--color-accent-dark); transform: translateY(-2px); box-shadow: var(--shadow-md); }
.btn-outline { border-color: var(--color-primary); color: var(--color-primary); }
.btn-outline:hover { background: var(--color-primary); color: #fff; }
.btn-light { background: #fff; color: var(--color-primary); }
.btn-light:hover { background: var(--color-bg-soft); transform: translateY(-2px); }

/* ===== Header ===== */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  transition: all 0.3s ease;
}
.site-header.scrolled { box-shadow: var(--shadow-sm); }
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand .logo {
  width: 40px; height: 40px;
  border-radius: 9px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  display: flex; align-items: center; justify-content: center;
  color: #fff; font-weight: 700; font-size: 18px;
  flex-shrink: 0;
}
.brand .name { font-weight: 700; font-size: 17px; color: var(--color-primary); line-height: 1.2; }
.brand .name small { display: block; font-size: 11px; font-weight: 400; color: var(--color-text-soft); letter-spacing: 0.5px; }

.nav-links { display: flex; align-items: center; gap: 34px; }
.nav-links a {
  font-size: 15px;
  color: var(--color-text);
  font-weight: 500;
  position: relative;
  transition: color 0.2s;
}
.nav-links a::after {
  content: "";
  position: absolute;
  left: 0; bottom: -6px;
  width: 0; height: 2px;
  background: var(--color-accent);
  transition: width 0.25s ease;
}
.nav-links a:hover, .nav-links a.active { color: var(--color-primary); }
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }

.nav-toggle { display: none; flex-direction: column; gap: 5px; cursor: pointer; background: none; border: none; }
.nav-toggle span { width: 24px; height: 2px; background: var(--color-primary); transition: 0.3s; }

/* ===== Hero ===== */
.hero {
  position: relative;
  padding: 150px 0 110px;
  background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary) 55%, var(--color-primary-light) 100%);
  color: #fff;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  right: -120px; top: -120px;
  width: 480px; height: 480px;
  background: radial-gradient(circle, rgba(200,146,58,0.28), transparent 70%);
  border-radius: 50%;
}
.hero::after {
  content: "";
  position: absolute;
  left: -160px; bottom: -180px;
  width: 420px; height: 420px;
  background: radial-gradient(circle, rgba(255,255,255,0.07), transparent 70%);
  border-radius: 50%;
}
.hero .container { position: relative; z-index: 2; }
.hero h1 {
  font-size: 46px;
  line-height: 1.25;
  font-weight: 700;
  margin-bottom: 22px;
  max-width: 760px;
}
.hero h1 .hl { color: var(--color-accent); }
.hero p.lead {
  font-size: 18px;
  color: rgba(255,255,255,0.85);
  max-width: 620px;
  margin-bottom: 36px;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-stats {
  display: flex;
  gap: 48px;
  margin-top: 64px;
  flex-wrap: wrap;
}
.hero-stats .stat .num { font-size: 34px; font-weight: 700; color: var(--color-accent); }
.hero-stats .stat .label { font-size: 14px; color: rgba(255,255,255,0.75); }

/* ===== Section ===== */
.section { padding: 90px 0; }
.section.soft { background: var(--color-bg-soft); }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 56px; }
.section-head .eyebrow {
  display: inline-block;
  color: var(--color-accent);
  font-weight: 600;
  font-size: 14px;
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 12px;
}
.section-head h2 { font-size: 34px; font-weight: 700; color: var(--color-primary); margin-bottom: 14px; }
.section-head p { color: var(--color-text-soft); font-size: 16px; }

/* ===== Cards / Grid ===== */
.grid { display: grid; gap: 28px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }

.card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 36px 30px;
  transition: all 0.3s ease;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-md); border-color: transparent; }
.card .icon {
  width: 56px; height: 56px;
  border-radius: 14px;
  background: var(--color-bg-soft);
  color: var(--color-primary);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 22px;
  font-size: 26px;
}
.card h3 { font-size: 20px; color: var(--color-primary); margin-bottom: 12px; }
.card p { color: var(--color-text-soft); font-size: 15px; }

.feature-list li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 10px 0;
  color: var(--color-text-soft);
}
.feature-list li::before {
  content: "✓";
  color: var(--color-accent);
  font-weight: 700;
  flex-shrink: 0;
}

/* ===== About split ===== */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}
.split .media {
  border-radius: var(--radius-lg);
  min-height: 420px;
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-primary-dark));
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}
.split .media .badge {
  color: #fff;
  text-align: center;
  padding: 30px;
}
.split .media .badge .big { font-size: 80px; font-weight: 800; color: var(--color-accent); line-height: 1; }
.split .media .badge .small { font-size: 16px; opacity: 0.85; margin-top: 10px; letter-spacing: 2px; }
.split .content h2 { font-size: 32px; color: var(--color-primary); margin-bottom: 18px; }
.split .content p { color: var(--color-text-soft); margin-bottom: 16px; }

/* ===== Timeline ===== */
.timeline { position: relative; max-width: 760px; margin: 0 auto; }
.timeline::before {
  content: "";
  position: absolute; left: 18px; top: 6px; bottom: 6px;
  width: 2px; background: var(--color-border);
}
.timeline .item { position: relative; padding: 0 0 36px 60px; }
.timeline .item::before {
  content: "";
  position: absolute; left: 9px; top: 6px;
  width: 20px; height: 20px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 4px solid #fff;
  box-shadow: 0 0 0 2px var(--color-accent);
}
.timeline .item .year { font-weight: 700; color: var(--color-primary); font-size: 18px; }
.timeline .item h4 { font-size: 17px; margin: 4px 0 6px; }
.timeline .item p { color: var(--color-text-soft); font-size: 15px; }

/* ===== Product detail ===== */
.product {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 32px;
  padding: 34px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: #fff;
  margin-bottom: 24px;
  transition: all 0.3s;
}
.product:hover { box-shadow: var(--shadow-md); border-color: transparent; }
.product .picon {
  width: 200px; height: 160px;
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--color-bg-soft), #eef2f7);
  display: flex; align-items: center; justify-content: center;
  font-size: 52px;
}
.product h3 { color: var(--color-primary); font-size: 22px; margin-bottom: 8px; }
.product .ptag { display: inline-block; font-size: 12px; color: var(--color-accent); background: #fbf3e6; padding: 3px 12px; border-radius: 50px; margin-bottom: 12px; }
.product p { color: var(--color-text-soft); margin-bottom: 14px; }
.product .specs { display: flex; gap: 28px; flex-wrap: wrap; }
.product .specs div { font-size: 14px; }
.product .specs div b { color: var(--color-primary); display: block; font-size: 17px; }

/* ===== Contact ===== */
.contact-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; }
.contact-info .item { display: flex; gap: 16px; margin-bottom: 26px; }
.contact-info .item .ic {
  width: 48px; height: 48px; flex-shrink: 0;
  border-radius: 12px; background: var(--color-bg-soft);
  display: flex; align-items: center; justify-content: center;
  font-size: 22px; color: var(--color-primary);
}
.contact-info .item h4 { font-size: 16px; color: var(--color-primary); }
.contact-info .item p { color: var(--color-text-soft); font-size: 15px; }

.form-group { margin-bottom: 20px; }
.form-group label { display: block; font-size: 14px; font-weight: 600; color: var(--color-primary); margin-bottom: 8px; }
.form-group input, .form-group textarea {
  width: 100%;
  padding: 13px 16px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 15px;
  font-family: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
  background: #fff;
}
.form-group input:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(200,146,58,0.12);
}
.form-group textarea { resize: vertical; min-height: 120px; }
.form-note { font-size: 13px; color: var(--color-text-soft); margin-top: 10px; }
.form-success {
  display: none;
  background: #eaf6ef;
  border: 1px solid #bfe3cd;
  color: var(--color-success);
  padding: 14px 18px;
  border-radius: var(--radius);
  margin-top: 16px;
  font-size: 15px;
}
.form-success.show { display: block; }

/* ===== CTA band ===== */
.cta-band {
  background: linear-gradient(135deg, var(--color-primary-dark), var(--color-primary));
  color: #fff;
  border-radius: var(--radius-lg);
  padding: 56px 50px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.cta-band::before {
  content: "";
  position: absolute; right: -60px; top: -60px;
  width: 240px; height: 240px;
  background: radial-gradient(circle, rgba(200,146,58,0.3), transparent 70%);
  border-radius: 50%;
}
.cta-band h2 { font-size: 30px; margin-bottom: 14px; position: relative; z-index: 2; }
.cta-band p { color: rgba(255,255,255,0.85); margin-bottom: 28px; position: relative; z-index: 2; }

/* ===== Footer ===== */
.site-footer {
  background: var(--color-bg-dark);
  color: rgba(255,255,255,0.7);
  padding: 60px 0 28px;
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1.4fr; gap: 40px; }
.footer-grid h4 { color: #fff; font-size: 16px; margin-bottom: 18px; }
.footer-grid .brand .name { color: #fff; }
.footer-grid .brand .name small { color: rgba(255,255,255,0.55); }
.footer-grid p { font-size: 14px; margin-bottom: 10px; }
.footer-grid a { font-size: 14px; display: block; padding: 5px 0; transition: color 0.2s; }
.footer-grid a:hover { color: var(--color-accent); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  margin-top: 40px;
  padding-top: 22px;
  text-align: center;
  font-size: 13px;
  color: rgba(255,255,255,0.5);
}

/* ===== Reveal animation ===== */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ===== Responsive ===== */
@media (max-width: 960px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .split, .contact-wrap { grid-template-columns: 1fr; gap: 36px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero h1 { font-size: 38px; }
}
@media (max-width: 680px) {
  .nav-links {
    position: fixed;
    top: 72px; left: 0; right: 0;
    background: #fff;
    flex-direction: column;
    gap: 0;
    padding: 10px 0;
    box-shadow: var(--shadow-md);
    transform: translateY(-130%);
    transition: transform 0.3s ease;
  }
  .nav-links.open { transform: none; }
  .nav-links a { padding: 14px 24px; width: 100%; }
  .nav-links a::after { display: none; }
  .nav-toggle { display: flex; }
  .grid-3, .grid-4, .grid-2 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero { padding: 120px 0 80px; }
  .hero h1 { font-size: 30px; }
  .hero-stats { gap: 28px; }
  .product { grid-template-columns: 1fr; }
  .product .picon { width: 100%; }
  .section { padding: 60px 0; }
  .section-head h2 { font-size: 27px; }
}