/* 山东建通工程科技有限公司 - 官网样式 */
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif; color: #333; line-height: 1.8; background: #fff; }
a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
ul, ol { list-style: none; }
.container { max-width: 1680px; margin: 0 auto; padding: 0 30px; }

/* 顶部信息栏 */
.top-bar { background: #1a3a5c; color: #fff; font-size: 13px; padding: 8px 0; }
.top-bar .container { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; }
.top-bar a { color: #fff; margin-left: 20px; }
.top-bar .phone { font-weight: bold; color: #ffd700; font-size: 15px; }

/* 导航栏 */
.header { background: #fff; box-shadow: 0 2px 8px rgba(0,0,0,0.08); position: sticky; top: 0; z-index: 100; }
.header .container { display: flex; justify-content: space-between; align-items: center; height: 80px; }
.logo { display: flex; align-items: center; gap: 12px; }
.logo-text { font-size: 22px; font-weight: bold; color: #1a3a5c; }
.logo-text small { display: block; font-size: 11px; color: #888; font-weight: normal; letter-spacing: 2px; }
.nav { display: flex; gap: 30px; }
.nav a { font-size: 15px; color: #333; padding: 8px 0; border-bottom: 2px solid transparent; transition: all 0.3s; }
.nav a:hover, .nav a.active { color: #c8a45c; border-bottom-color: #c8a45c; }

/* 顶部Banner图 */
.top-banner { width: 100%; height: 600px; overflow: hidden; position: relative; }
.top-banner img { width: 100%; height: 100%; object-fit: cover; display: block; }
.top-banner .banner-overlay { position: absolute; top: 0; left: 0; width: 100%; height: 100%; background: linear-gradient(90deg, rgba(26,58,92,0.75) 0%, rgba(26,58,92,0.3) 60%, transparent 100%); display: flex; align-items: center; }
.top-banner .banner-content { max-width: 1680px; margin: 0 auto; padding: 0 30px; width: 100%; }
.top-banner .banner-content h1 { font-size: 44px; color: #fff; margin-bottom: 16px; text-shadow: 0 2px 8px rgba(0,0,0,0.3); }
.top-banner .banner-content p { font-size: 20px; color: rgba(255,255,255,0.95); max-width: 700px; margin-bottom: 30px; text-shadow: 0 1px 4px rgba(0,0,0,0.3); }
.top-banner .banner-content .btn { display: inline-block; background: #c8a45c; color: #fff; padding: 14px 40px; border-radius: 4px; font-size: 17px; font-weight: bold; transition: background 0.3s; }
.top-banner .banner-content .btn:hover { background: #b8944c; }

/* Banner */
.banner { background: linear-gradient(135deg, #1a3a5c 0%, #2c5f8a 100%); color: #fff; padding: 80px 0; text-align: center; }
.banner h1 { font-size: 38px; margin-bottom: 16px; }
.banner p { font-size: 18px; opacity: 0.9; max-width: 800px; margin: 0 auto 30px; }
.banner .btn { display: inline-block; background: #c8a45c; color: #fff; padding: 12px 36px; border-radius: 4px; font-size: 16px; font-weight: bold; transition: background 0.3s; }
.banner .btn:hover { background: #b8944c; }

/* 通用区块 */
.section { padding: 60px 0; }
.section-title { text-align: center; margin-bottom: 40px; }
.section-title h2 { font-size: 30px; color: #1a3a5c; margin-bottom: 10px; }
.section-title p { color: #888; font-size: 15px; }
.section-title .line { width: 60px; height: 3px; background: #c8a45c; margin: 15px auto 0; }

/* 子导航栏 */
.sub-nav { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; margin-top: 24px; margin-bottom: 10px; }
.sub-nav a { display: inline-block; padding: 8px 20px; background: #fff; border: 1px solid #d0dde8; border-radius: 20px; font-size: 14px; color: #1a3a5c; transition: all 0.3s; }
.sub-nav a:hover { background: #1a3a5c; color: #fff; border-color: #1a3a5c; }

/* 产品展示 */
.products { background: #f8f9fa; }
.product-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.product-card { background: #fff; border-radius: 8px; overflow: hidden; box-shadow: 0 2px 12px rgba(0,0,0,0.06); transition: transform 0.3s, box-shadow 0.3s; }
.product-card:hover { transform: translateY(-5px); box-shadow: 0 8px 24px rgba(0,0,0,0.12); }
.product-card .img-box { aspect-ratio: 4/3; background: linear-gradient(135deg, #e8eef4, #d0dde8); display: flex; align-items: center; justify-content: center; overflow: hidden; }
.product-card .img-box img { width: 100%; height: 100%; object-fit: cover; }
.product-card .info { padding: 20px; }
.product-card h3 { font-size: 18px; color: #1a3a5c; margin-bottom: 8px; }
.product-card p { font-size: 13px; color: #666; line-height: 1.6; }

/* 案例展示 */
.case-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 20px; }
.case-card { border: 1px solid #e0e0e0; border-radius: 8px; overflow: hidden; transition: all 0.3s; }
.case-card:hover { border-color: #c8a45c; box-shadow: 0 4px 16px rgba(200,164,92,0.15); }
.case-card .img-box { aspect-ratio: 4/3; background: linear-gradient(135deg, #2c5f8a, #1a3a5c); display: flex; align-items: center; justify-content: center; color: #fff; font-size: 16px; text-align: center; padding: 20px; overflow: hidden; }
.case-card .img-box img { width: 100%; height: 100%; object-fit: cover; }
.case-card .info { padding: 20px; }
.case-card h3 { font-size: 17px; color: #1a3a5c; margin-bottom: 8px; }
.case-card p { font-size: 13px; color: #666; }

/* 分站导航 */
.substations { background: #f8f9fa; }
.region-group { margin-bottom: 30px; }
.region-group h3 { font-size: 18px; color: #1a3a5c; margin-bottom: 12px; padding-left: 12px; border-left: 4px solid #c8a45c; }
.region-links { display: flex; flex-wrap: wrap; gap: 10px; }
.region-links a { display: inline-block; padding: 8px 18px; background: #fff; border: 1px solid #ddd; border-radius: 4px; font-size: 14px; color: #333; transition: all 0.3s; }
.region-links a:hover { background: #1a3a5c; color: #fff; border-color: #1a3a5c; }

/* 公司介绍 */
.about { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center; }
.about-text h2 { font-size: 28px; color: #1a3a5c; margin-bottom: 20px; }
.about-text p { margin-bottom: 15px; color: #555; font-size: 15px; }
.about-text .highlight { color: #c8a45c; font-weight: bold; }
.about-img { aspect-ratio: 4/3; background: linear-gradient(135deg, #1a3a5c, #2c5f8a); border-radius: 8px; display: flex; align-items: center; justify-content: center; color: #fff; font-size: 20px; text-align: center; overflow: hidden; }
.about-img img { width: 100%; height: 100%; object-fit: cover; }

/* 资讯列表 */
.news-list { max-width: 100%; margin: 0 auto; display: grid; grid-template-columns: 1fr 1fr; gap: 0 40px; }
.news-item { display: flex; justify-content: space-between; align-items: center; padding: 14px 0; border-bottom: 1px dashed #e0e0e0; }
.news-item a { font-size: 15px; color: #333; flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.news-item a:hover { color: #c8a45c; }
.news-item .date { color: #999; font-size: 13px; margin-left: 20px; white-space: nowrap; }

/* 联系我们 */
.contact { background: #1a3a5c; color: #fff; }
.contact .section-title h2 { color: #fff; }
.contact .section-title p { color: rgba(255,255,255,0.7); }
.contact-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 30px; text-align: center; }
.contact-item h4 { font-size: 16px; margin-bottom: 10px; color: #c8a45c; }
.contact-item p { font-size: 15px; opacity: 0.9; }
.contact-item .big-phone { font-size: 28px; font-weight: bold; color: #ffd700; }

/* 页脚 */
.footer { background: #0f2540; color: rgba(255,255,255,0.7); padding: 50px 0 0; font-size: 14px; }
.footer-top { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; padding-bottom: 40px; border-bottom: 1px solid rgba(255,255,255,0.1); }
.footer-col h4 { color: #fff; font-size: 16px; margin-bottom: 18px; padding-bottom: 10px; border-bottom: 2px solid #c8a45c; display: inline-block; }
.footer-col p { margin-bottom: 10px; line-height: 1.8; }
.footer-col a { color: rgba(255,255,255,0.7); display: block; margin-bottom: 8px; transition: color 0.3s; }
.footer-col a:hover { color: #c8a45c; }
.footer-col .phone-big { font-size: 24px; color: #ffd700; font-weight: bold; margin: 8px 0; }
.footer-qrcode { text-align: center; }
.footer-qrcode .qr-box { width: 140px; height: 140px; margin: 0 auto 12px; background: #fff; border-radius: 8px; padding: 8px; display: flex; align-items: center; justify-content: center; }
.footer-qrcode .qr-box img { width: 100%; height: 100%; object-fit: contain; }
.footer-qrcode p { font-size: 13px; color: rgba(255,255,255,0.6); }
.footer-bottom { text-align: center; padding: 20px 0; font-size: 13px; color: rgba(255,255,255,0.5); }
.footer-bottom p { margin-bottom: 6px; }
.footer-bottom a { color: rgba(255,255,255,0.5); }
.footer-bottom a:hover { color: #c8a45c; }
.footer-bottom .beian-link { margin: 0 8px; }

/* 省份页面特色 */
.province-hero { background: linear-gradient(135deg, #1a3a5c 0%, #2c5f8a 100%); color: #fff; padding: 60px 0; text-align: center; }
.province-hero h1 { font-size: 32px; margin-bottom: 12px; }
.province-hero p { font-size: 16px; opacity: 0.9; }
.breadcrumb { background: #f5f5f5; padding: 12px 0; font-size: 13px; color: #666; }
.breadcrumb a { color: #1a3a5c; }
.breadcrumb span { margin: 0 8px; color: #ccc; }

/* 省份页面内容 */
.province-content { padding: 40px 0; }
.province-content h2 { font-size: 24px; color: #1a3a5c; margin: 30px 0 15px; padding-bottom: 8px; border-bottom: 2px solid #c8a45c; }
.province-content h2:first-child { margin-top: 0; }
.province-content h3 { font-size: 19px; color: #2c5f8a; margin: 20px 0 10px; }
.province-content p { margin-bottom: 12px; color: #444; font-size: 15px; }
.province-content ul { padding-left: 20px; margin-bottom: 15px; }
.province-content li { margin-bottom: 8px; color: #444; list-style: disc; }
.province-content .info-box { background: #f0f5fa; border-left: 4px solid #c8a45c; padding: 20px; margin: 20px 0; border-radius: 0 4px 4px 0; }
.province-content .info-box h4 { color: #1a3a5c; margin-bottom: 10px; }

/* 关键词标签 */
.keyword-tags { display: flex; flex-wrap: wrap; gap: 8px; margin: 15px 0; }
.keyword-tags span { background: #e8eef4; color: #1a3a5c; padding: 4px 12px; border-radius: 20px; font-size: 13px; }

/* 响应式 */
/* ========== 响应式适配 ========== */

/* 平板及以下 (≤1024px) */
@media (max-width: 1024px) {
  .container { padding: 0 20px; }
  .top-banner .banner-content { padding: 0 20px; }
  .case-grid { grid-template-columns: repeat(3, 1fr); }
  .footer-top { grid-template-columns: 1fr 1fr; gap: 30px; }
  .top-banner { height: 450px; }
  .top-banner .banner-content h1 { font-size: 34px; }
  .top-banner .banner-content p { font-size: 17px; }
}

/* 手机横屏/小平板 (≤768px) */
@media (max-width: 768px) {
  .container { padding: 0 15px; max-width: 100%; }
  .top-banner .banner-content { padding: 0 15px; }

  /* 顶部信息栏 */
  .top-bar { font-size: 12px; padding: 6px 0; }
  .top-bar .container { flex-direction: column; gap: 4px; text-align: center; }
  .top-bar .phone { font-size: 14px; }

  /* 导航栏 */
  .header .container { height: 60px; }
  .logo-text { font-size: 17px; }
  .logo-text small { font-size: 9px; letter-spacing: 1px; }
  .nav { display: none; }

  /* 顶部Banner */
  .top-banner { height: 320px; }
  .top-banner .banner-content h1 { font-size: 24px; margin-bottom: 10px; }
  .top-banner .banner-content p { font-size: 14px; margin-bottom: 20px; line-height: 1.6; }
  .top-banner .banner-content .btn { padding: 10px 24px; font-size: 14px; }
  .banner { padding: 50px 0; }
  .banner h1 { font-size: 24px; }
  .banner p { font-size: 15px; }

  /* 通用区块 */
  .section { padding: 35px 0; }
  .section-title h2 { font-size: 22px; }
  .section-title p { font-size: 13px; }

  /* 子导航栏 */
  .sub-nav { gap: 6px; margin-top: 16px; }
  .sub-nav a { padding: 5px 12px; font-size: 12px; }

  /* 产品网格 3列→2列 */
  .product-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .product-card .info { padding: 12px; }
  .product-card h3 { font-size: 15px; }
  .product-card p { font-size: 12px; }

  /* 案例网格 5列→2列 */
  .case-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .case-card .info { padding: 12px; }
  .case-card h3 { font-size: 14px; }
  .case-card p { font-size: 12px; }

  /* 关于我们 */
  .about { grid-template-columns: 1fr; gap: 20px; }
  .about-text h2 { font-size: 22px; }
  .about-text p { font-size: 14px; }

  /* 资讯两列→一列 */
  .news-list { grid-template-columns: 1fr; gap: 0; }
  .news-item { padding: 10px 0; }
  .news-item a { font-size: 14px; }
  .news-item .date { font-size: 12px; margin-left: 10px; }

  /* 联系我们 */
  .contact-grid { grid-template-columns: 1fr; gap: 20px; }
  .contact-item .big-phone { font-size: 22px; }

  /* 分站导航 */
  .region-group h3 { font-size: 16px; }
  .region-links { gap: 6px; }
  .region-links a { padding: 6px 12px; font-size: 13px; }

  /* 省份页面 */
  .province-hero { padding: 40px 0; }
  .province-hero h1 { font-size: 22px; }
  .province-hero p { font-size: 14px; }
  .province-content { padding: 25px 0; }
  .province-content h2 { font-size: 20px; }
  .province-content h3 { font-size: 17px; }
  .province-content p { font-size: 14px; }
  .keyword-tags { gap: 6px; }
  .keyword-tags span { padding: 3px 10px; font-size: 12px; }
  .info-box { padding: 15px; }

  /* 页脚 */
  .footer { padding: 30px 0 0; }
  .footer-top { grid-template-columns: 1fr; gap: 25px; padding-bottom: 25px; }
  .footer-col h4 { font-size: 15px; margin-bottom: 12px; }
  .footer-col p { font-size: 13px; }
  .footer-col a { font-size: 13px; margin-bottom: 6px; }
  .footer-col .phone-big { font-size: 20px; }
  .footer-qrcode .qr-box { width: 120px; height: 120px; }
  .footer-bottom { padding: 15px 0; font-size: 12px; }
  .footer-bottom .beian-link { margin: 0 4px; }

  /* 面包屑 */
  .breadcrumb { padding: 8px 0; font-size: 12px; }
}

/* 手机竖屏 (≤480px) */
@media (max-width: 480px) {
  .container { padding: 0 12px; }
  .top-banner .banner-content { padding: 0 12px; }

  .top-bar { font-size: 11px; }
  .logo-text { font-size: 15px; }
  .logo-text small { display: none; }

  .top-banner { height: 260px; }
  .top-banner .banner-content h1 { font-size: 20px; }
  .top-banner .banner-content p { font-size: 13px; }
  .top-banner .banner-content .btn { padding: 8px 20px; font-size: 13px; }

  .section { padding: 25px 0; }
  .section-title h2 { font-size: 19px; }
  .section-title p { font-size: 12px; }

  /* 产品/案例 2列→1列 */
  .product-grid { grid-template-columns: 1fr; gap: 10px; }
  .case-grid { grid-template-columns: 1fr; gap: 10px; }

  .sub-nav { gap: 5px; }
  .sub-nav a { padding: 4px 10px; font-size: 11px; }

  .province-hero h1 { font-size: 19px; }
  .province-content h2 { font-size: 18px; }
  .province-content h3 { font-size: 16px; }

  .region-links a { padding: 5px 10px; font-size: 12px; }
}