/* ==========================================================================
   泰汇尔仪器 - 现代企业站样式
   字体：系统栈 + 中文雅黑/微软雅黑
   主色：品牌暗红 #9B1B1B（取自公司 logo）  深红 #6E1111  暗金 #C79A2A  墨蓝黑 #1B2230
   ========================================================================== */
:root{
  --primary:#9B1B1B;
  --primary-2:#6E1111;
  --accent:#C79A2A;
  --dark:#1B2230;
  --gray:#f4f6f8;
  --text:#333;
  --muted:#7d8999;
  --line:#e8e6ed;
  --radius:8px;
  --shadow:0 4px 18px rgba(27,34,48,.08);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei","PingFang SC",sans-serif;color:var(--text);line-height:1.7;background:#fff}
a{color:var(--primary-2);text-decoration:none;transition:color .2s}
a:hover{color:var(--accent)}
img{max-width:100%;display:block}
.container{width:100%;max-width:1200px;margin:0 auto;padding:0 15px}
h1,h2,h3,h4{color:var(--primary);font-weight:700;line-height:1.3}

/* 顶部工具栏 —— 品牌红 */
.topbar{background:linear-gradient(90deg,var(--primary-2),var(--primary));color:#f7e7e7;font-size:13px}
.topbar-inner{display:flex;justify-content:space-between;align-items:center;height:34px}
.topbar b{color:var(--accent);font-size:14px}

/* 头部 + 导航 */
.header{background:#fff;box-shadow:var(--shadow);position:sticky;top:0;z-index:100}
.header-inner{display:flex;justify-content:space-between;align-items:center;height:74px}
.logo a.logo-link{display:flex;align-items:center;gap:12px}
.logo-badge{width:46px;height:46px;flex:none;display:block}
.logo-img{height:46px;width:auto;max-width:220px;object-fit:contain;display:block}
.logo-text{display:flex;flex-direction:column;line-height:1.15}
.logo-name{font-size:22px;color:var(--primary);font-weight:800;letter-spacing:1px}
.logo-desc{font-size:11px;color:var(--muted);margin-top:3px;letter-spacing:2px}
.main-nav{display:flex;align-items:center;gap:4px}
.nav-item{padding:26px 16px;color:var(--text);font-size:15px;position:relative}
.nav-item:hover,.nav-item.active{color:var(--accent)}
.nav-item.active:after,.nav-item:hover:after{content:"";position:absolute;left:12px;right:12px;bottom:16px;height:3px;background:var(--accent);border-radius:2px}
.nav-toggle{display:none;font-size:26px;cursor:pointer;color:var(--primary)}

/* 产品中心多列悬停下拉（子栏目横排 / 子栏目的子目录纵排、缩略图） */
.nav-has-mega{position:relative}
.nav-has-mega .nav-caret{font-style:normal;font-size:11px;margin-left:4px;color:var(--muted)}
.nav-has-mega:hover .nav-caret{color:var(--accent)}
.mega{position:absolute;top:100%;left:50%;transform:translateX(-50%);display:none;z-index:300;padding-top:12px;min-width:760px}
.nav-has-mega:hover .mega{display:block}
.mega-panel{background:#fff;border:1px solid var(--line);border-radius:var(--radius);box-shadow:0 14px 40px rgba(27,34,48,.16);display:flex;gap:24px;padding:30px 32px;width:max-content;max-width:980px}
.mega-col{min-width:168px}
.mega-col-title{display:block;font-size:18px;font-weight:700;color:var(--primary);padding:6px 6px 14px;margin-bottom:10px;border-bottom:2px solid var(--gray);white-space:nowrap}
.mega-col-title:hover{color:var(--primary-2)}
.mega-items{display:flex;flex-direction:column;gap:10px}
.mega-item{display:flex;align-items:center;gap:12px;padding:9px 6px;border-radius:8px;color:var(--text);font-size:15px;line-height:1.35;transition:background .15s}
.mega-item:hover{background:var(--gray);color:var(--primary)}
.mega-thumb{width:58px;height:58px;border-radius:8px;overflow:hidden;background:#eee;flex:none;border:1px solid var(--line)}
.mega-thumb img{width:100%;height:100%;object-fit:cover}
.mega-name{white-space:normal;font-weight:600}
.mega-empty{color:var(--muted);font-size:13px;padding:6px 6px}

/* 关于泰汇尔 / 服务与支持：小下拉 */
.nav-has-drop{position:relative}
.nav-has-drop .nav-caret{font-style:normal;font-size:11px;margin-left:4px;color:var(--muted)}
.nav-has-drop:hover .nav-caret{color:var(--accent)}
.drop{position:absolute;top:100%;left:50%;transform:translateX(-50%);display:none;z-index:300;padding-top:12px;min-width:180px;text-align:left}
.nav-has-drop:hover .drop{display:block}
.drop a.drop-item{display:block;background:#fff;border:1px solid var(--line);border-top:0;padding:13px 20px;color:var(--text);font-size:15px;white-space:nowrap;box-shadow:0 12px 30px rgba(27,34,48,.14);width:100%}
.drop a.drop-item:first-child{border-top:1px solid var(--line);border-radius:6px 6px 0 0}
.drop a.drop-item:last-child{border-radius:0 0 6px 6px}
.drop a.drop-item:hover{background:var(--gray);color:var(--primary)}

/* 主横幅 */
.hero{position:relative;overflow:hidden;background:var(--dark)}
.hero-slide{position:relative;min-height:380px;display:flex;align-items:center}
.hero-slide .bg{position:absolute;inset:0;background-size:cover;background-position:center;opacity:.35;filter:blur(1px)}
.hero-slide .inner{position:relative;z-index:2;color:#fff;max-width:1200px;margin:0 auto;padding:20px 15px;width:100%}
.hero-slide h1{color:#fff;font-size:40px;margin-bottom:14px}
.hero-slide p{font-size:17px;color:#dbe4ef;max-width:720px;margin-bottom:22px}
.hero-cta{padding:12px 30px;background:var(--primary);color:#fff;border-radius:50px;font-size:16px;display:inline-block;transition:background .2s}
.hero-cta:hover{background:var(--primary-2)}
.hero-dots{position:absolute;bottom:20px;left:0;right:0;display:flex;justify-content:center;gap:8px;z-index:3}
.hero-dots span{width:10px;height:10px;border-radius:50%;background:rgba(255,255,255,.5);cursor:pointer}
.hero-dots span.on{background:var(--accent)}

/* 板块 */
.section{padding:56px 0}
.section .sec-head{display:flex;justify-content:space-between;align-items:flex-end;margin-bottom:28px;border-bottom:2px solid var(--line);padding-bottom:14px}
.section .sec-title{font-size:24px;position:relative}
.section .sec-title small{display:block;font-size:13px;color:var(--muted);font-weight:400;margin-top:4px}
.section .sec-link{font-size:14px;color:var(--muted)}
.section.bg{background:var(--gray)}

/* 产品网格 */
.grid{display:grid;gap:20px}
.grid-4{grid-template-columns:repeat(4,1fr)}
.grid-3{grid-template-columns:repeat(3,1fr)}
.card{background:#fff;border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);border:1px solid var(--line);transition:transform .25s,box-shadow .25s}
.card:hover{transform:translateY(-4px);box-shadow:0 10px 26px rgba(27,34,48,.14)}
.card .thumb{aspect-ratio:1/1;overflow:hidden;background:#fff;padding:12px;display:flex;align-items:center;justify-content:center}
.card .thumb img{max-width:100%;max-height:100%;object-fit:contain;transition:transform .3s}
.card:hover .thumb img{transform:scale(1.05)}
.card .bd{padding:14px 16px}
.card .bd h3{font-size:15px;margin-bottom:4px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.card .bd p{font-size:13px;color:var(--muted);height:40px;overflow:hidden}

/* 新闻列表 */
.news-list{list-style:none;display:grid;gap:14px}
.news-list li{display:flex;justify-content:space-between;gap:16px;border-bottom:1px dashed var(--line);padding-bottom:12px}
.news-list a{color:var(--text);font-size:15px}
.news-list a:hover{color:var(--accent)}
.news-list time{color:var(--muted);font-size:13px;white-space:nowrap}

/* 首页新闻双栏：左新闻列表 + 右资料下载/视频教程面板 */
.news-wrap{display:grid;grid-template-columns:1.9fr 1fr;gap:26px;align-items:start}
.news-main{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:20px 24px;box-shadow:var(--shadow)}
.news-main .news-list{gap:0}
.news-main .news-list li:nth-child(n+8){display:none}
.news-main .news-list li:first-child a{color:var(--primary);font-weight:600}
.news-aside{display:grid;gap:20px}
.panel{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:18px 20px;box-shadow:var(--shadow)}
.panel-title{font-size:16px;color:var(--primary);font-weight:700;margin-bottom:6px;display:flex;align-items:center;gap:8px;padding-bottom:10px;border-bottom:2px solid var(--gray)}
.panel-list{list-style:none}
.panel-list li{display:flex;align-items:center;gap:8px;padding:9px 0;border-bottom:1px dashed var(--line)}
.panel-list li:last-child{border-bottom:0}
.panel-list .dot{width:6px;height:6px;border-radius:50%;background:var(--accent);flex:none}
.panel-list a{font-size:14px;color:var(--text);flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.panel-list a:hover{color:var(--primary)}
.video-label{background:var(--primary);color:#fff;font-size:11px;line-height:1;padding:3px 7px;border-radius:4px;flex:none}
.panel-more{display:inline-block;margin-top:10px;font-size:13px;color:var(--primary);font-weight:600}
.panel-more:hover{color:var(--primary-2)}

/* 多功能面板/功能卡片 */
.features{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;margin-top:8px}
.feature{display:block;text-align:center;padding:30px 16px;background:#fff;border-radius:var(--radius);border:1px solid var(--line);cursor:pointer;transition:transform .22s,box-shadow .22s,border-color .22s}
.feature:hover{transform:translateY(-5px);box-shadow:0 12px 28px rgba(27,34,48,.13);border-color:var(--primary)}
.feature .ico{width:60px;height:60px;margin:0 auto 14px;border-radius:16px;display:flex;align-items:center;justify-content:center;font-size:28px;color:#fff;background:linear-gradient(135deg,var(--primary-2),var(--primary));transition:transform .22s}
.feature:hover .ico{transform:scale(1.08)}
.feature h3{font-size:16px;margin-bottom:6px}
.feature p{font-size:13px;color:var(--muted)}

/* 页面内副标题（标题居中） */
.page-banner{padding:44px 0;background:linear-gradient(135deg,var(--primary),var(--primary-2));color:#fff;text-align:center}
.page-banner h1{color:#fff;font-size:28px;margin-bottom:6px}
.page-banner .crumb{color:#c7d4e5;font-size:13px}
.crumb a{color:#c7d4e5}.crumb a:hover{color:#fff}

/* 左右布局 */
.layout{display:grid;grid-template-columns:280px 1fr;gap:30px;padding:34px 0}
.sidebar{background:#fff;border:1px solid var(--line);border-radius:var(--radius);align-self:start;overflow:hidden}
.sidebar .sb-title{background:var(--primary);color:#fff;padding:14px 18px;font-size:16px}
.sidebar ul{list-style:none}
.sidebar ul a{display:block;padding:12px 18px;border-bottom:1px solid var(--line);color:var(--text);font-size:14px}
.sidebar ul a:hover,.sidebar ul a.active{color:var(--primary);background:var(--gray);padding-left:22px;font-weight:600}
.sidebar .sb-sub{max-height:0;overflow:hidden;transition:max-height .3s}
.sidebar .sb-sub.open{max-height:600px}
.sidebar .sb-sub a{padding:9px 18px 9px 34px;font-size:13px;color:var(--muted);border-bottom:0;position:relative}
.sidebar .sb-sub a:before{content:"";position:absolute;left:20px;top:50%;width:6px;height:6px;border-radius:50%;background:var(--line);transform:translateY(-50%)}
.sidebar .sb-sub a:hover:before,.sidebar .sb-sub a.active:before{background:var(--primary)}
.sidebar .sb-sub a.active{color:var(--primary);font-weight:600}
.sidebar .sb-main.has-sub>a:after{content:"›";float:right;color:var(--muted);font-size:12px;line-height:1.4}
.sidebar .sb-main.has-sub>a.active:after{color:var(--primary)}
.content{min-width:0}

/* 分页 */
.pagination{display:flex;justify-content:center;gap:8px;margin-top:34px;flex-wrap:wrap}
.pagination a,.pagination span{padding:7px 14px;border:1px solid var(--line);border-radius:6px;font-size:14px;color:var(--text)}
.pagination .on{background:var(--primary);color:#fff;border-color:var(--primary)}
.pagination a:hover{border-color:var(--primary-2);color:var(--primary-2)}

/* 详情页 */
.article{padding:34px 0}
.article-h1{font-size:24px;margin-bottom:10px;text-align:center}
.article-meta{color:var(--muted);font-size:13px;padding-bottom:16px;border-bottom:1px solid var(--line);margin-bottom:22px;display:flex;gap:18px;flex-wrap:wrap;justify-content:center}
.article-body{font-size:15px;line-height:1.9}
.article-body img{border-radius:6px;margin:8px auto}
.article-body p{margin-bottom:14px}
.article-body table{width:100%;border-collapse:collapse;margin:16px 0}
.article-body td,.article-body th{border:1px solid var(--line);padding:8px 12px;font-size:14px}
.article-body th{background:var(--gray)}
.article-body h2,.article-body h3,.article-body h4{margin:18px 0 10px}

/* 图册 */
.photo-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.photo-item{border-radius:var(--radius);overflow:hidden;border:1px solid var(--line);position:relative}
.photo-item img{aspect-ratio:4/3;object-fit:cover;width:100%}
.photo-item .cap{position:absolute;left:0;right:0;bottom:0;background:linear-gradient(transparent,rgba(27,34,48,.88));color:#fff;padding:30px 12px 10px;font-size:14px}

/* 联系页 */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:34px}
.contact-info li{list-style:none;padding:12px 0;border-bottom:1px dashed var(--line);font-size:15px}
.contact-info b{color:var(--primary);margin-right:6px}

/* 页脚 */
.footer{background:linear-gradient(180deg,var(--primary-2),#4a0a0c);color:#ecd8d9;margin-top:10px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr;gap:44px;padding:46px 0}
.footer h4{color:#fff;font-size:16px;margin-bottom:16px}
.footer ul{list-style:none}
.footer ul li{margin-bottom:9px}
.footer ul a{color:#f2e2e3}
.footer ul a:hover{color:var(--accent)}
.footer-contact-col{border-left:1px solid rgba(255,255,255,.1);padding-left:30px}
/* 页脚产品中心：大栏目横排 / 大栏目下方子目录竖排 */
.footer-prod-cols{display:flex;gap:38px;flex-wrap:wrap}
.footer-prod-col{min-width:120px;max-width:200px}
.fp-title{display:block;color:#fff;font-weight:700;font-size:15px;margin-bottom:12px;border-left:3px solid var(--accent);padding-left:8px;line-height:1.3}
.fp-title:hover{color:var(--accent)}
.fp-list li{margin-bottom:7px}
.fp-list a{color:#e6cccd;font-size:13px}
.fp-list a:hover{color:#fff;text-decoration:underline}
.fp-none{color:rgba(255,255,255,.3)}
.footer-bottom{border-top:1px solid rgba(255,255,255,.08);padding:16px 0;font-size:13px;display:flex;justify-content:space-between;color:#fff}
.footer-bottom a{color:#fff}
.footer-bottom a:hover{color:#ffd99a}
.footer-bottom .footer-sitemap{color:#ffe08a;font-weight:700;text-decoration:underline;margin-left:14px}

/* 响应式 */
@media(max-width:900px){
  .grid-4,.grid-3{grid-template-columns:repeat(2,1fr)}
  .features{grid-template-columns:repeat(2,1fr)}
  .layout{grid-template-columns:1fr}
  .news-wrap{grid-template-columns:1fr}
  .contact-grid,.footer-grid{grid-template-columns:1fr}
  .hero-slide h1{font-size:28px}
  .nav-toggle{display:block}
  .main-nav{position:fixed;top:74px;left:0;right:0;background:#fff;flex-direction:column;align-items:stretch;display:none;box-shadow:var(--shadow);overflow:auto;max-height:calc(100vh - 74px)}
  .main-nav.open{display:flex}
  .nav-item{padding:16px;border-bottom:1px solid var(--line)}
  /* 移动端：产品中心下拉改为站内展开（点击菜单后直接看到子分类） */
  .nav-has-mega{position:static}
  .mega{position:static;display:block;padding:0;min-width:0;background:var(--gray)}
  .mega-panel{flex-direction:column;gap:8px;padding:4px 8px 14px;width:auto;max-width:none;border:0;box-shadow:none;border-radius:0}
  .mega-col{min-width:0}
  .mega-item{padding-left:12px}
  /* 移动端：关于泰汇尔/服务与支持下拉改为站内展开 */
  .nav-has-drop{position:static}
  .drop{position:static;display:block;padding:0;min-width:0;background:var(--gray);box-shadow:none;text-align:left}
  .drop a.drop-item{background:transparent;border:0;border-radius:0;box-shadow:none;padding:9px 24px;font-size:14px;color:var(--muted);white-space:normal}
  .drop a.drop-item:first-child,.drop a.drop-item:last-child{border-radius:0}
  .footer-contact-col{border-left:0;padding-left:0}
  .footer-prod-cols{gap:22px}
  .photo-grid{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:560px){
  .grid-4,.grid-3,.features{grid-template-columns:1fr}
  .photo-grid{grid-template-columns:1fr}
}