:root{
  --navy:#10244B;
  --navy-2:#1b3568;
  --ink:#353535;
  --body:#4b4b4b;
  --muted:#a9a9a9;
  --line:#e7e6e2;
  --alt:#f6f5f1;
  --white:#ffffff;
}
*{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;}
body{
  font-family:"Microsoft YaHei","PingFang SC","Hiragino Sans GB","Source Han Sans CN",sans-serif;
  color:var(--body);
  background:var(--white);
  line-height:1.7;
  -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none;}
img{display:block;max-width:100%;}
.wrap{width:1200px;max-width:92%;margin:0 auto;}

/* 顶栏 */
.topbar{background:var(--white);border-bottom:1px solid var(--line);}
.topbar .wrap{display:flex;align-items:center;justify-content:space-between;height:92px;}
.topbar .logo img{height:150px;width:auto;}
.lang{font-size:13px;color:var(--body);}
.lang a{color:var(--body);padding:0 4px;}
.lang a.cur{color:var(--navy);font-weight:700;}
.lang .sep{color:var(--muted);}

/* 导航 */
.mainnav{background:var(--navy);position:sticky;top:0;z-index:50;}
.mainnav ul{list-style:none;display:flex;flex-wrap:wrap;}
.mainnav li{flex:1 1 auto;text-align:center;}
.mainnav a{
  display:block;padding:18px 22px;color:#dfe4ee;font-size:16px;letter-spacing:1px;
  transition:background .2s,color .2s;border-bottom:3px solid transparent;
}
.mainnav li a.active{background:var(--navy-2);color:#fff;border-bottom-color:#c2a05a;}
  .mainnav a:hover{background:var(--navy-2);color:#fff;}

  /* 移动端汉堡导航（桌面端隐藏触发键） */
  .nav-shell{position:relative;}
  .nav-wrap{display:flex;align-items:center;justify-content:space-between;}
  .nav-burger{display:none;color:#fff;font-size:26px;line-height:1;cursor:pointer;padding:13px 4px;background:none;border:0;-webkit-tap-highlight-color:transparent;}
  .nav-list{display:flex;list-style:none;flex-wrap:wrap;width:100%;}
  .mainnav .nav-list li{flex:1 1 auto;text-align:center;}

/* 通栏按钮 */
.btn{
  display:inline-block;background:var(--navy);color:#fff;font-size:15px;
  padding:11px 30px;border-radius:2px;letter-spacing:2px;transition:background .2s;
}
.btn:hover{background:var(--navy-2);}
.btn.ghost{background:transparent;color:var(--navy);border:1px solid var(--navy);}
.btn.ghost:hover{background:var(--navy);color:#fff;}

/* 首页横幅 */
.banner{height:600px;background:url("assets/banner-no-text.jpg") center/cover no-repeat;}

/* ============ 子页通用 ============ */
.subbanner{
  background:linear-gradient(120deg,var(--navy) 0%,var(--navy-2) 100%);
  color:#fff;padding:64px 0 54px;position:relative;overflow:hidden;
}
.subbanner::after{
  content:"";position:absolute;right:-60px;top:-60px;width:340px;height:340px;
  background:radial-gradient(circle,rgba(194,160,90,.18),transparent 70%);
}
.subbanner h1{font-size:42px;letter-spacing:4px;font-weight:700;position:relative;}
.subbanner .crumb{margin-top:14px;font-size:14px;color:#b9c2d6;position:relative;}
.subbanner .crumb a{color:#b9c2d6;}
.subbanner .crumb a:hover{color:#fff;}
.subbanner .crumb span{margin:0 8px;color:#7d8aa8;}

/* 子导航（走进天源二级） */
.subnav{background:var(--alt);border-bottom:1px solid var(--line);}
.subnav ul{list-style:none;display:flex;flex-wrap:wrap;gap:0;}
.subnav a{display:block;padding:16px 30px;font-size:15px;color:var(--body);letter-spacing:1px;border-bottom:3px solid transparent;}
.subnav a:hover{color:var(--navy);}
.subnav a.active{color:var(--navy);font-weight:700;border-bottom-color:#c2a05a;}

section{padding:64px 0;}
.sec-head{margin-bottom:34px;}
.sec-head h2{font-size:40px;color:var(--ink);font-weight:700;letter-spacing:2px;line-height:1.2;}
.sec-head .sub{font-size:16px;color:var(--body);margin-top:8px;letter-spacing:1px;}
.sec-head.center{text-align:center;}
.sec-head.center .sub{color:var(--muted);}

/* 产品推荐 */
.prod-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:22px;}
.prod figure{background:#fff;border:1px solid var(--line);overflow:hidden;transition:box-shadow .2s,transform .2s;}
.prod figure:hover{box-shadow:0 10px 26px rgba(0,0,0,.12);transform:translateY(-3px);}
.prod .ph{aspect-ratio:335/358;overflow:hidden;background:var(--alt);}
.prod .ph img{width:100%;height:100%;object-fit:cover;}
.prod figcaption{text-align:center;padding:14px 6px;font-size:16px;color:var(--ink);letter-spacing:1px;}
.prod-more{text-align:right;margin-top:26px;}

/* 精雕细琢 */
.about .wrap{display:grid;grid-template-columns:1.1fr .9fr;gap:40px;align-items:center;}
.about h2{font-size:48px;color:var(--navy);font-weight:700;line-height:1.15;letter-spacing:3px;margin-bottom:22px;}
.about p{font-size:16px;color:var(--body);margin-bottom:14px;line-height:2;}
.about .prod-line{margin-top:6px;}
.about .intro img{border:1px solid var(--line);width:100%;}
.about .act{margin-top:24px;}

/* 我们的优势 */
.advantages{background:var(--alt);}
.adv-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:26px;margin-top:14px;}
.adv{text-align:center;padding:10px;}
.adv .ic{width:90px;height:90px;margin:0 auto 16px;object-fit:contain;}
.adv h3{font-size:17px;color:var(--body);font-weight:700;margin-bottom:10px;letter-spacing:1px;}
.adv p{font-size:13px;color:var(--muted);line-height:1.9;}

/* 精选案例（首页深色区） */
.cases{background:#16181d;color:#fff;}
.cases .sec-head h2{color:#fff;}
.cases .sec-head .sub{color:#cfd2d8;}
.case-banner{margin:8px 0 26px;}
.case-banner img{width:100%;height:300px;object-fit:cover;}
.case-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;}
.case-grid figure{overflow:hidden;border:1px solid #2b2e36;background:#1f2228;}
.case-grid .ph{aspect-ratio:1/1;overflow:hidden;}
.case-grid .ph img{width:100%;height:100%;object-fit:cover;transition:transform .4s;}
.case-grid figure:hover .ph img{transform:scale(1.06);}
.case-more{text-align:right;margin-top:24px;}
.case-more .btn{background:#fff;color:var(--navy);}
.case-more .btn:hover{background:var(--navy);color:#fff;}

/* 天源头条 */
.news-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:22px;margin-top:8px;}
.news figure{border:1px solid var(--line);background:#fff;overflow:hidden;transition:box-shadow .2s;}
.news figure:hover{box-shadow:0 10px 26px rgba(0,0,0,.1);}
.news .ph{aspect-ratio:16/10;overflow:hidden;background:var(--alt);}
.news .ph img{width:100%;height:100%;object-fit:cover;}
.news figcaption{padding:16px 14px;font-size:15px;color:var(--ink);line-height:1.6;min-height:78px;}
.news .date{display:block;font-size:12px;color:var(--muted);margin-top:8px;}
.news-card a{display:block;}
.news-card a:hover figcaption{color:var(--navy);}

/* 文章正文（关于/头条详情） */
.article{max-width:860px;margin:0 auto;}
.article h2{font-size:26px;color:var(--ink);margin:28px 0 14px;letter-spacing:1px;}
.article h3{font-size:20px;color:var(--ink);margin:22px 0 10px;}
.article p{font-size:16px;color:var(--body);line-height:2;margin-bottom:16px;text-align:justify;}
.article img{max-width:100%;margin:18px 0;border:1px solid var(--line);}
.article .lead{font-size:18px;color:var(--ink);}
.article ul{margin:0 0 16px 22px;}
.article ul li{margin-bottom:8px;}

/* 案例列表（工程案例页） */
.case-list{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;}
.case-item{border:1px solid var(--line);overflow:hidden;background:#fff;transition:box-shadow .2s;}
.case-item:hover{box-shadow:0 10px 26px rgba(0,0,0,.12);}
.case-item .ph{aspect-ratio:4/3;overflow:hidden;background:var(--alt);}
.case-item .ph img{width:100%;height:100%;object-fit:cover;}
.case-item .meta{padding:18px 18px 22px;}
.case-item .meta h3{font-size:18px;color:var(--ink);margin-bottom:8px;letter-spacing:1px;}
.case-item .meta p{font-size:14px;color:var(--muted);line-height:1.8;}

/* 产品详情 */
.pd{display:grid;grid-template-columns:.9fr 1.1fr;gap:44px;align-items:start;}
.pd .gallery .main-img{border:1px solid var(--line);overflow:hidden;}
.pd .gallery .main-img img{width:100%;}
.pd .thumbs{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-top:12px;}
.pd .thumbs img{border:1px solid var(--line);cursor:pointer;}
.pd h1{font-size:34px;color:var(--ink);letter-spacing:2px;margin-bottom:10px;}
.pd .tag{display:inline-block;background:var(--navy);color:#fff;font-size:13px;padding:4px 14px;border-radius:2px;letter-spacing:1px;margin-bottom:18px;}
.pd .price{font-size:20px;color:#c0392b;margin:6px 0 18px;}
.pd .price small{color:var(--muted);font-size:13px;}
.pd p{font-size:15px;color:var(--body);line-height:2;margin-bottom:14px;}
.pd table{width:100%;border-collapse:collapse;margin:14px 0 22px;font-size:14px;}
.pd table th,.pd table td{border:1px solid var(--line);padding:11px 14px;text-align:left;}
.pd table th{background:var(--alt);color:var(--ink);width:120px;font-weight:700;}
.pd .act{margin-top:10px;display:flex;gap:14px;flex-wrap:wrap;}

/* 车间设备图文 */
.equip{display:grid;grid-template-columns:repeat(2,1fr);gap:30px;margin-top:10px;}
.equip .item{border:1px solid var(--line);overflow:hidden;background:#fff;}
.equip .item .ph{aspect-ratio:16/10;overflow:hidden;background:var(--alt);}
.equip .item .ph img{width:100%;height:100%;object-fit:cover;}
.equip .item .meta{padding:18px 20px 22px;}
.equip .item h3{font-size:19px;color:var(--ink);margin-bottom:8px;letter-spacing:1px;}
.equip .item p{font-size:14px;color:var(--body);line-height:1.9;}

/* 联系我们 */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:start;}
.contact-info h3{font-size:18px;color:var(--ink);margin:18px 0 8px;letter-spacing:1px;}
.contact-info p{font-size:15px;color:var(--body);line-height:2;}
.contact-info .big{font-size:22px;color:var(--navy);font-weight:700;letter-spacing:1px;}
.map-box{height:340px;background:var(--alt);border:1px solid var(--line);display:flex;align-items:center;justify-content:center;color:var(--muted);font-size:15px;}
.form-box{background:var(--alt);border:1px solid var(--line);padding:28px;}
.form-box label{display:block;font-size:14px;color:var(--ink);margin:14px 0 6px;letter-spacing:1px;}
.form-box input,.form-box textarea{
  width:100%;padding:11px 12px;border:1px solid var(--line);font-size:15px;font-family:inherit;
  background:#fff;color:var(--body);border-radius:2px;
}
.form-box textarea{resize:vertical;min-height:110px;}
.form-box .btn{margin-top:18px;width:100%;text-align:center;border:none;cursor:pointer;}

/* 荣誉 / 架构 */
.honor-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;}
.honor{border:1px solid var(--line);background:#fff;text-align:center;padding:24px 16px;}
.honor .ph{height:140px;display:flex;align-items:center;justify-content:center;background:var(--alt);margin-bottom:14px;overflow:hidden;}
.honor .ph img{max-height:140px;width:auto;}
.honor h3{font-size:16px;color:var(--ink);letter-spacing:1px;}
.honor p{font-size:13px;color:var(--muted);margin-top:6px;}
.org-flow{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;text-align:center;}
.org-flow .node{background:var(--navy);color:#fff;padding:22px 12px;border-radius:3px;letter-spacing:1px;font-size:16px;}
.org-flow .node small{display:block;color:#b9c2d6;font-size:12px;margin-top:8px;letter-spacing:0;}

/* 页脚 */
footer{background:var(--navy);color:#c9cfdb;font-size:13px;padding:30px 0;text-align:center;line-height:2;}
footer a{color:#c9cfdb;}
footer .sep{color:#55617e;margin:0 8px;}
footer .copy{margin-bottom:6px;}

/* ============ 移动端适配 ============ */
@media (max-width:1024px){
  section{padding:52px 0;}
  .prod-grid,.adv-grid,.case-grid,.news-grid{grid-template-columns:repeat(2,1fr);}
  .case-list,.honor-grid{grid-template-columns:repeat(2,1fr);}
  .about .wrap,.pd,.contact-grid{grid-template-columns:1fr;}
  .equip,.org-flow{grid-template-columns:repeat(2,1fr);}
  .banner{height:440px;}
  .sec-head h2,.about h2{font-size:32px;}
  .subbanner h1{font-size:30px;letter-spacing:2px;}
  .sec-head{margin-bottom:26px;}
}

@media (max-width:768px){
  .wrap{width:auto;max-width:100%;padding:0 16px;}
  .topbar .wrap{height:64px;}
  .topbar .logo img{height:46px;}
  .lang{font-size:12px;}

  /* 汉堡菜单 */
  .nav-burger{display:block;}
  .mainnav .nav-list{
    display:none;flex-direction:column;width:100%;
    position:absolute;left:0;top:100%;background:var(--navy);
    box-shadow:0 10px 24px rgba(0,0,0,.28);padding:6px 0;
  }
  .mainnav .nav-list li{flex:none;width:100%;text-align:left;}
  .mainnav .nav-list a{
    padding:15px 18px;border-bottom:1px solid rgba(255,255,255,.08);
    font-size:15px;letter-spacing:1px;
  }
  .mainnav .nav-list li:first-child a{border-bottom:1px solid rgba(255,255,255,.08);}
  .nav-toggle-cb:checked ~ .mainnav .nav-list,
  .mainnav .nav-list.open{display:flex;}

  section{padding:44px 0;}
  .sec-head{margin-bottom:22px;}
  .sec-head h2,.about h2{font-size:25px;letter-spacing:1px;}
  .subbanner{padding:46px 0 40px;}
  .subbanner h1{font-size:23px;letter-spacing:1px;}
  .subbanner::after{width:200px;height:200px;right:-40px;top:-40px;}
  .banner{height:300px;}
  .about h2{font-size:28px;}
  .prod figcaption{font-size:15px;}
  .case-banner img{height:200px;}
  .prod-more,.case-more{text-align:center;}
  .form-box{padding:20px;}
  footer{font-size:12px;padding:24px 0;}
  footer .wrap>div:last-child{line-height:2.3;}
}

@media (max-width:480px){
  .prod-grid,.adv-grid,.case-grid,.news-grid,
  .case-list,.honor-grid,.equip,.org-flow{grid-template-columns:1fr;}
  .sec-head h2{font-size:21px;}
  .about h2{font-size:24px;}
  .news figcaption{min-height:0;}
  .adv .ic{width:74px;height:74px;}
  .subbanner h1{font-size:20px;}
}