/* 整站布局：导航 / Banner / 页脚 */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --font-main: "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  --color-primary: #1a5fb4;
  --color-primary-dark: #0d4a8f;
  --color-dark: #1a1a1a;
  --color-gray: #666;
  --color-light-gray: #f5f5f5;
  --color-white: #fff;
  --header-height: 72px;
  --container-max: 1400px;
  --transition: 0.3s ease;
}

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-main);
  color: var(--color-dark);
  line-height: 1.6;
}

a { text-decoration: none; color: inherit; transition: color var(--transition); }
ul { list-style: none; }
img {  display: block; }

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

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  font-size: 14px;
  font-weight: 600;
  border-radius: 4px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: background var(--transition), color var(--transition), border-color var(--transition), transform 0.15s ease, box-shadow var(--transition);
}
.btn:active { transform: scale(0.97); }
.btn-primary { background: var(--color-primary); color: var(--color-white); border-color: var(--color-primary); }
.btn-primary:hover { background: var(--color-primary-dark); box-shadow: 0 4px 16px rgba(26,95,180,0.35); }
.btn-light { background: var(--color-white); color: var(--color-dark); border-color: var(--color-white); }
.btn-light:hover { background: transparent; color: var(--color-white); border-color: var(--color-white); }

.section-heading { font-size: 32px; font-weight: 700; margin-bottom: 12px; }
.section-subheading { font-size: 16px; color: var(--color-gray); }

/* Header */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(255,255,255,0.97);
  backdrop-filter: blur(8px);
  box-shadow: 0 1px 0 rgba(0,0,0,0.08);
  height: var(--header-height);
}
.header-inner {
  max-width: var(--container-max); margin: 0 auto; padding: 0 24px;
  height: 100%; display: flex; align-items: center; justify-content: space-between; gap: 24px;
}
.logo { display: flex; align-items: center; gap: 10px; }
.logo-icon {
  width: 36px; height: 36px; background: var(--color-primary); color: var(--color-white);
  border-radius: 6px; display: flex; align-items: center; justify-content: center; font-size: 16px;
}
.logo-text { font-size: 18px; font-weight: 700; }
.logo-text em { font-style: normal; color: var(--color-primary); font-weight: 600; }
.main-nav { flex: 1; display: flex; justify-content: center; }
.nav-list { display: flex; gap: 4px; }
.nav-link {
  display: block; padding: 8px 12px; font-size: 13px; font-weight: 500;
  color: var(--color-gray); border-radius: 4px;
  transition: color var(--transition), background var(--transition);
}
.nav-link:hover, .nav-link.active { color: var(--color-primary); background: rgba(26,95,180,0.08); }
.header-cta { padding: 10px 20px; font-size: 13px; flex-shrink: 0; }
.nav-toggle {
  display: none; flex-direction: column; gap: 5px; width: 36px; height: 36px;
  background: none; border: none; cursor: pointer; padding: 4px;
}
.nav-toggle span { display: block; width: 100%; height: 2px; background: var(--color-dark); border-radius: 2px; transition: transform var(--transition), opacity var(--transition); }
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Banner */
.banner { position: relative; margin-top: var(--header-height); height: 520px; overflow: hidden; }
.banner-slider { position: relative; width: 100%; height: 100%; }
.banner-slide { position: absolute; inset: 0; opacity: 0; transition: opacity 0.8s ease; pointer-events: none; }
.banner-slide.active { opacity: 1; pointer-events: auto; }
.banner-bg { position: absolute; inset: 0; background-size: cover; background-position: center top; transform: scale(1.05); transition: transform 6s ease; }
.banner-slide.active .banner-bg { transform: scale(1); }
.banner-overlay { position: absolute; inset: 0; background: linear-gradient(105deg, rgba(0,0,0,0.65) 0%, rgba(0,0,0,0.2) 60%, transparent 100%); }
.banner-content {
  position: absolute; inset: 0; display: flex; flex-direction: column; justify-content: center;
  padding: 0 72px; max-width: 640px; color: var(--color-white);
}
.banner-tag { font-size: 13px; font-weight: 600; letter-spacing: 2px; text-transform: uppercase; color: rgba(255,255,255,0.75); margin-bottom: 14px; }
.banner-title { font-size: 40px; font-weight: 700; line-height: 1.2; margin-bottom: 14px; }
.banner-desc { font-size: 16px; color: rgba(255,255,255,0.85); margin-bottom: 28px; line-height: 1.7; }
.banner-arrow {
  position: absolute; top: 50%; transform: translateY(-50%);
  width: 44px; height: 44px; background: rgba(255,255,255,0.15); border: 1px solid rgba(255,255,255,0.3);
  border-radius: 50%; color: var(--color-white); cursor: pointer; z-index: 10;
  display: flex; align-items: center; justify-content: center;
  transition: background var(--transition), transform 0.15s ease;
}
.banner-arrow:hover { background: rgba(255,255,255,0.3); }
.banner-arrow:active { transform: translateY(-50%) scale(0.93); }
.banner-prev { left: 20px; }
.banner-next { right: 20px; }
.banner-dots { position: absolute; bottom: 24px; left: 50%; transform: translateX(-50%); display: flex; gap: 10px; z-index: 10; }
.banner-dot { width: 10px; height: 10px; border-radius: 50%; background: rgba(255,255,255,0.4); border: none; cursor: pointer; padding: 0; transition: background var(--transition), transform 0.15s ease; }
.banner-dot.active { background: var(--color-white); transform: scale(1.2); }

/* Products intro */
.products-intro { padding: 64px 0 32px; text-align: center; background: var(--color-light-gray); }
.product-nav-cards { display: grid; grid-template-columns: repeat(6, 1fr); gap: 14px; margin-top: 40px; }
.product-nav-card {
  border-radius: 6px; overflow: hidden; background: var(--color-white);
  box-shadow: 0 2px 10px rgba(0,0,0,0.08);
  transition: transform var(--transition), box-shadow var(--transition);
}
.product-nav-card:hover { transform: translateY(-4px); box-shadow: 0 8px 20px rgba(0,0,0,0.12); }
.product-nav-card img { width: 100%; height: 90px; object-fit: cover; object-position: center top; }
.product-nav-card span { display: block; padding: 10px 6px; font-size: 11px; font-weight: 600; text-align: center; }

/* Module separator */
.module-divider { height: 1px; background: #e8e8e8; max-width: var(--container-max); margin: 0 auto; }

/* About */
.about-section { padding: 72px 0; background: var(--color-light-gray); }
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
.about-text p { font-size: 15px; color: var(--color-gray); line-height: 1.8; margin-bottom: 14px; }
.about-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.stat-item { background: var(--color-white); padding: 28px 16px; text-align: center; border-radius: 8px; box-shadow: 0 2px 10px rgba(0,0,0,0.06); transition: transform var(--transition); }
.stat-item:hover { transform: translateY(-4px); }
.stat-item strong { display: block; font-size: 34px; font-weight: 700; color: var(--color-primary); margin-bottom: 6px; }
.stat-item span { font-size: 13px; color: var(--color-gray); }

/* Footer */
.site-footer { background: #111; color: rgba(255,255,255,0.75); padding: 56px 0 0; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1.5fr; gap: 36px; padding-bottom: 40px; border-bottom: 1px solid rgba(255,255,255,0.1); }
.footer-logo .logo-text { color: var(--color-white); }
.footer-desc { font-size: 14px; line-height: 1.7; margin: 14px 0 20px; }
.footer-social { display: flex; gap: 10px; }
.footer-social a {
  width: 34px; height: 34px; border: 1px solid rgba(255,255,255,0.2); border-radius: 50%;
  display: flex; align-items: center; justify-content: center; font-size: 13px;
  color: rgba(255,255,255,0.7); transition: background var(--transition), color var(--transition);
}
.footer-social a:hover { background: var(--color-primary); color: var(--color-white); }
.footer-col h4 { font-size: 13px; font-weight: 700; color: var(--color-white); text-transform: uppercase; letter-spacing: 1px; margin-bottom: 16px; }
.footer-col ul li { margin-bottom: 8px; }
.footer-col ul li a { font-size: 14px; color: rgba(255,255,255,0.6); }
.footer-col ul li a:hover { color: var(--color-white); }
.footer-contact li { display: flex; gap: 10px; font-size: 14px; align-items: flex-start; }
.footer-contact i { color: var(--color-primary); margin-top: 3px; }
.footer-bottom { padding: 20px 0; text-align: center; font-size: 13px; color: rgba(255,255,255,0.4); }

@media (max-width: 991px) {
  .main-nav {
    position: fixed; top: var(--header-height); left: 0; right: 0;
    background: var(--color-white); box-shadow: 0 8px 24px rgba(0,0,0,0.12);
    padding: 16px 24px; transform: translateY(-110%); opacity: 0;
    transition: transform var(--transition), opacity var(--transition); pointer-events: none;
  }
  .main-nav.open { transform: translateY(0); opacity: 1; pointer-events: auto; }
  .nav-list { flex-direction: column; }
  .nav-toggle { display: flex; }
  .header-cta { display: none; }
  .banner { height: 400px; }
  .banner-content { padding: 0 28px; }
  .banner-title { font-size: 26px; }
  .product-nav-cards { grid-template-columns: repeat(3, 1fr); }
  .about-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 575px) {
  .banner { height: 340px; }
  .banner-title { font-size: 22px; }
  .product-nav-cards { grid-template-columns: repeat(2, 1fr); }
  .about-stats { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
}