* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Microsoft YaHei", sans-serif;
}
:root {
  --main: #2E8B8B;
  --light: #4CAF8B;
  --dark: #1A4A5A;
  --text: #333;
  --gray: #666;
  --border: #eee;
}
body {
  color: var(--text);
  line-height: 1.8;
}
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 15px;
}
header {
  position: sticky;
  top: 0;
  background: #fff;
  box-shadow: 0 2px 5px rgba(0,0,0,0.05);
  z-index: 999;
}
.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}
.logo {
  font-size: 22px;
  font-weight: bold;
  color: var(--main);
  text-decoration: none;
}

/* 导航 */
.nav-menu {
  display: flex;
  list-style: none;
}
.nav-menu > li {
  margin-left: 30px;
  position: relative;
  display: flex;
  align-items: center;
  gap: 6px;
}
.nav-menu a {
  color: #333;
  text-decoration: none;
  font-size: 15px;
}
.nav-menu a:hover {
  color: var(--main);
}

/* 小箭头 */
.caret {
  font-size: 12px;
  color: #666;
  cursor: pointer;
  user-select: none;
}

/* 二级默认 隐藏！！！ */
.subnav {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 160px;
  background: #fff;
  box-shadow: 0 3px 10px rgba(0,0,0,0.1);
  padding: 10px 0;
  list-style: none;
  display: none;
}
.subnav li {
  padding: 5px 15px;
}
.subnav a {
  font-size: 14px;
}

/* 移动端按钮 */
.mobile-btn {
  display: none;
  font-size: 24px;
  background: none;
  border: none;
  color: var(--main);
}

/* 以下样式保持不变 */
section { padding:60px 0; }
.sec-title { text-align:center; margin-bottom:40px; font-size:28px; color:var(--main); }
.btn { display:inline-block; padding:12px 28px; background:var(--light); color:#fff; border-radius:4px; text-decoration:none; }
.position { padding:15px 0; font-size:14px; color:var(--gray); }
.product-grid { display:grid; grid-template-columns:repeat(3,1fr); gap:30px; }
.product-item { text-align:center; }
.product-item img { width:100%; height:auto; border-radius:8px; }
.news-list { max-width:900px; margin:0 auto; }
.news-item { padding:18px 0; border-bottom:1px dashed var(--border); }
.news-item a { display:flex; justify-content:space-between; color:var(--text); }
.page { text-align:center; padding:30px 0; }
.form-wrap { max-width:750px; margin:0 auto; background:#f7f7f7; padding:40px; border-radius:8px; }
.form-group { margin-bottom:20px; }
.form-group label { display:block; margin-bottom:8px; }
.form-group input,.form-group textarea,.form-group select { width:100%; padding:12px; border:1px solid #ddd; border-radius:4px; }
.map-box { width:100%; height:380px; background:#eee; border-radius:8px; overflow:hidden; }
footer { background:var(--dark); color:#fff; padding:40px 0 20px; text-align:center; margin-top:30px; }

@media (max-width:768px) {
  .nav-menu {
    position:fixed; top:70px; left:-100%; width:100%; height:100vh;
    background:#fff; flex-direction:column; padding:20px; transition:0.3s;
  }
  .nav-menu.show { left:0; }
  .nav-menu > li { margin:10px 0; }
  .subnav { position:static; display:none; padding-left:15px; box-shadow:none; }
  .mobile-btn { display:block; }
}
/* 移动端大图适配 */
@media (max-width:768px) {
  .hero { height:320px !important; }
  .hero h1 { font-size:26px !important; }
  .hero p { font-size:15px !important; }
}
/* 推荐产品：PC端3个，移动端自动竖排 */
@media (max-width:768px){
  .product-grid {
    grid-template-columns: 1fr !important;
  }
}