/* ===== 全局重置 ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 76px; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: #222; background: #fff; line-height: 1.6;
  padding-top: 76px; /* 给固定导航留位 */
}
img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ===== 顶部导航（桌面端） ===== */
#siteNav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: #ffffff; /* 纯白，完全不透明 */
  border-bottom: 1px solid #e8e8e8;
  transition: box-shadow 0.3s;
}
#siteNav.scrolled { box-shadow: 0 2px 12px rgba(0,0,0,0.08); }
.nav-inner {
  max-width: 1200px; margin: 0 auto; padding: 0 24px;
  display: flex; align-items: center; justify-content: space-between;
  height: 76px;
}
.nav-brand { display: flex; align-items: center; gap: 10px; }
.nav-brand img { width: 40px; height: 40px; }
.nav-brand span { font-size: 16px; font-weight: 600; color: #222; }

#navMenu { display: flex; align-items: center; gap: 28px; }
#navMenu a {
  font-size: 15px; color: #444; padding: 6px 0;
  border-bottom: 2px solid transparent;
  transition: color 0.2s, border-color 0.2s;
}
#navMenu a:hover { color: #3fae8f; }
#navMenu a.active { color: #3fae8f; border-bottom-color: #3fae8f; font-weight: 600; }

.nav-right { display: flex; align-items: center; gap: 16px; }
#navLang {
  background: none; border: 1px solid #ccc; border-radius: 4px;
  padding: 4px 10px; font-size: 13px; cursor: pointer; color: #555;
}
#navLang:hover { border-color: #3fae8f; color: #3fae8f; }

/* ===== 汉堡按钮（默认隐藏，手机端显示） ===== */
#navToggle {
  display: none; background: none; border: none; cursor: pointer;
  width: 32px; height: 32px; position: relative;
}
#navToggle span {
  display: block; width: 22px; height: 2px; background: #333;
  margin: 5px auto; transition: 0.3s; border-radius: 2px;
}
#navToggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
#navToggle.active span:nth-child(2) { opacity: 0; }
#navToggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== 页脚 ===== */
.site-footer {
  background: #fafafa; border-top: 1px solid #eee;
  padding: 48px 24px 32px; text-align: center;
}
.footer-brand { font-size: 34px; font-weight: 700; letter-spacing: 1px; }
.footer-brand .dot { color: #3fae8f; }
.footer-sub { font-size: 14px; color: #888; margin-top: 4px; }
.footer-social { margin-top: 16px; display: flex; justify-content: center; gap: 12px; }
.footer-social a {
  display: inline-flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; border-radius: 50%;
  background: #eee; color: #555; font-size: 14px;
  transition: 0.2s;
}
.footer-social a:hover { background: #3fae8f; color: #fff; }
.footer-motto {
  margin-top: 20px; font-size: 14px; color: #999;
  border-top: 1px solid #eee; padding-top: 16px;
}
.footer-copy { margin-top: 8px; font-size: 12px; color: #aaa; }

/* ===== 首页 ===== */
.hero {
  background: linear-gradient(135deg, #2d1b4e 0%, #4a2c6d 40%, #7b3f8f 100%);
  color: #fff; padding: 120px 0 80px; text-align: center;
}
.hero h1 { font-size: 42px; font-weight: 700; margin-bottom: 12px; }
.hero h1 span { color: #3fae8f; }
.hero p { font-size: 16px; opacity: 0.85; max-width: 600px; margin: 0 auto; }
.hero .en { font-size: 14px; opacity: 0.6; margin-top: 8px; font-style: italic; }

.section { padding: 80px 0; }
.section-title { font-size: 32px; font-weight: 700; text-align: center; margin-bottom: 16px; }
.section-sub { text-align: center; color: #888; margin-bottom: 40px; }

.intro-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center; }
.intro-text p { margin-bottom: 16px; color: #555; font-size: 15px; }
.intro-visual {
  background: linear-gradient(135deg, #0f766e, #14b8a6);
  border-radius: 16px; padding: 60px 40px; text-align: center; color: #fff;
  min-height: 300px; display: flex; align-items: center; justify-content: center;
  font-size: 18px;
}

.world-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.world-item {
  background: #f8f8f8; border-radius: 12px; padding: 40px 24px;
  text-align: center; transition: 0.2s;
}
.world-item:hover { transform: translateY(-4px); box-shadow: 0 8px 24px rgba(0,0,0,0.08); }
.world-item .icon { font-size: 48px; margin-bottom: 12px; }
.world-item h3 { font-size: 16px; margin-bottom: 8px; }
.world-item p { font-size: 13px; color: #888; }

.learn-section { background: #1a1a1a; color: #fff; }
.learn-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center; }
.learn-grid h2 { font-size: 28px; margin-bottom: 12px; }
.learn-grid p { color: #aaa; font-size: 14px; margin-bottom: 16px; }
.btn-primary {
  display: inline-block; background: #3fae8f; color: #fff;
  padding: 10px 28px; border-radius: 24px; font-size: 14px;
  transition: 0.2s; border: none; cursor: pointer;
}
.btn-primary:hover { background: #358f76; }

.contact-section { background: #fafafa; }
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.contact-info h3 { font-size: 20px; margin-bottom: 16px; }
.contact-info p { margin-bottom: 12px; color: #555; font-size: 14px; }
.contact-info .icon { margin-right: 8px; }
.contact-form label { display: block; font-size: 14px; margin-bottom: 6px; color: #555; }
.contact-form input, .contact-form textarea {
  width: 100%; padding: 10px 14px; border: 1px solid #ddd;
  border-radius: 6px; font-size: 14px; margin-bottom: 16px;
  font-family: inherit;
}
.contact-form input:focus, .contact-form textarea:focus {
  outline: none; border-color: #3fae8f;
}
.contact-form textarea { min-height: 120px; resize: vertical; }

/* ===== 关于页 ===== */
.page-hero { padding: 80px 0 40px; text-align: center; }
.page-hero h1 { font-size: 36px; font-weight: 700; }
.page-hero p { color: #888; margin-top: 8px; }
.about-block { padding: 40px 0; border-bottom: 1px solid #eee; }
.about-block h2 { font-size: 24px; margin-bottom: 8px; }
.about-block .en { color: #3fae8f; font-size: 14px; margin-bottom: 16px; }
.about-block p { color: #555; font-size: 15px; margin-bottom: 12px; }
.timeline { border-left: 3px solid #3fae8f; padding-left: 24px; margin: 20px 0; }
.timeline-item { margin-bottom: 16px; position: relative; }
.timeline-item::before {
  content: ""; position: absolute; left: -29px; top: 6px;
  width: 10px; height: 10px; border-radius: 50%;
  background: #3fae8f;
}
.timeline-item .year { font-weight: 700; color: #3fae8f; }
.quote-block {
  border-left: 4px solid #3fae8f; padding: 16px 20px;
  background: #f8f8f8; border-radius: 0 8px 8px 0; margin: 16px 0;
}
.add-image {
  border: 2px dashed #ccc; border-radius: 8px; padding: 40px;
  text-align: center; color: #aaa; margin: 16px 0; cursor: pointer;
}

/* ===== 商标页 ===== */
.brand-hero { text-align: center; padding: 80px 0 40px; }
.brand-hero h1 { font-size: 40px; }
.brand-hero p { color: #888; margin-top: 8px; }
.brand-showcase {
  display: flex; justify-content: center; gap: 60px; flex-wrap: wrap;
  padding: 40px 0;
}
.brand-card { text-align: center; max-width: 300px; }
.brand-card .logo-box {
  width: 180px; height: 180px; border-radius: 16px;
  background: #f0f0f0; display: flex; align-items: center;
  justify-content: center; margin: 0 auto 16px;
}
.brand-card h3 { font-size: 18px; margin-bottom: 8px; }
.brand-card p { font-size: 13px; color: #888; }

/* ===== 北美市场页 ===== */
.product-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; padding: 40px 0; }
.product-card { background: #fff; border: 1px solid #eee; border-radius: 12px; overflow: hidden; }
.product-card .img-box {
  background: #f8f8f8; padding: 40px; display: flex;
  align-items: center; justify-content: center; min-height: 280px;
}
.product-card .info { padding: 20px 24px; }
.product-card h3 { font-size: 16px; margin-bottom: 8px; }
.product-card .rating { color: #f59e0b; font-size: 14px; }
.product-card .price { font-size: 18px; font-weight: 700; margin: 8px 0; }
.product-card .desc { font-size: 13px; color: #888; }
.product-card .unavailable { color: #dc2626; font-size: 13px; }

/* =====================================================
   ===== 手机端导航栏（重点优化：完全不透明、清晰） =====
   ===================================================== */
@media (max-width: 768px) {
  body { padding-top: 64px; }

  /* 导航栏：纯白、不透明、加阴影 */
  #siteNav {
    background: #ffffff !important;  /* 强制纯白，完全覆盖背景 */
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.1);  /* 阴影让导航更立体 */
    border-bottom: 1px solid #e0e0e0;
  }

  .nav-inner { height: 64px; padding: 0 16px; }

  /* 品牌文字 */
  .nav-brand span {
    font-size: 15px;
    color: #222;
    font-weight: 700;
    white-space: nowrap;
  }

  /* 汉堡按钮：显示、加大点击区域 */
  #navToggle {
    display: block;
    width: 40px;
    height: 40px;
    padding: 4px;
    border-radius: 6px;
    background: transparent;
  }
  #navToggle span {
    width: 22px;
    height: 2.5px;
    background: #333;
    margin: 5px auto;
  }

  /* 语言切换按钮：更清晰 */
  #navLang {
    font-size: 13px;
    padding: 4px 10px;
    border: 1px solid #ccc;
    background: #fff;
    color: #333;
  }

  /* 菜单抽屉：纯白背景 + 高对比文字 */
  #navMenu {
    position: fixed;
    top: 64px;
    right: 0;
    bottom: 0;
    width: 280px;
    background: #ffffff !important;  /* 纯白，完全不透明 */
    flex-direction: column;
    padding: 30px 24px;
    gap: 8px;
    transform: translateX(100%);
    transition: transform 0.3s ease;
    box-shadow: -4px 0 24px rgba(0, 0, 0, 0.15);
    z-index: 999;
    display: flex;
    overflow-y: auto;
  }

  /* 菜单打开状态 */
  #navMenu.open {
    transform: translateX(0);
  }

  /* 菜单链接：大点击区域、高对比 */
  #navMenu a {
    display: block;
    font-size: 17px;
    font-weight: 500;
    color: #222;
    padding: 14px 12px;
    border-radius: 8px;
    border-bottom: none;
    transition: background 0.2s, color 0.2s;
  }

  /* 菜单链接点击效果 */
  #navMenu a:hover,
  #navMenu a:active {
    background: #f0f7f4;
    color: #3fae8f;
  }

  /* 当前激活菜单项 */
  #navMenu a.active {
    color: #3fae8f;
    background: #e8f5f0;
    font-weight: 700;
    border-bottom: none;
  }

  /* 菜单底部留白 */
  #navMenu li:last-child {
    margin-bottom: 20px;
  }

  /* 其它页面布局 */
  .nav-right { margin-left: auto; }
  .intro-grid, .learn-grid, .contact-grid, .product-grid { grid-template-columns: 1fr; }
  .world-grid { grid-template-columns: 1fr 1fr; }
  .hero h1 { font-size: 30px; }
  .hero { padding: 80px 0 60px; }
  .section { padding: 60px 0; }
  .footer-brand { font-size: 26px; }
}

/* ===== 超小屏（≤480px） ===== */
@media (max-width: 480px) {
  .container { padding: 0 16px; }
  .nav-inner { padding: 0 12px; }
  .hero h1 { font-size: 24px; }
  .hero p { font-size: 14px; }
  .section-title { font-size: 26px; }
  .world-grid { grid-template-columns: 1fr; }
  .footer-brand { font-size: 22px; }
  .footer-motto { font-size: 12px; }

  /* 菜单宽度适配小屏 */
  #navMenu {
    width: 85%;
    max-width: 300px;
    padding: 24px 20px;
  }
  #navMenu a {
    font-size: 16px;
    padding: 12px 10px;
  }
}