*{margin:0;padding:0;box-sizing:border-box}
  html,body{min-height:100%;} /* 让页面可以撑满屏幕，解决短内容留白 */
  body{font-family:"Microsoft YaHei","PingFang SC",sans-serif;color:#222;background:#fff;line-height:1.7;
    /* 删掉全局padding-bottom，改成仅移动端添加 */
  }
  a{text-decoration:none;color:#222}
  ul{list-style:none}
  img,svg{max-width:100%;height:auto;display:block}

  .container{width:94%;max-width:1200px;margin:0 auto}

  /* 顶部工具条 */
  .topbar{background:#f7f7f7;border-bottom:1px solid #eee;font-size:13px;color:#666;line-height:1.5}
  .topbar .topbar-in{display:flex;justify-content:space-between;align-items:center;padding:8px 0;flex-wrap:nowrap;width:100%;box-sizing:border-box}
  .topbar p{flex:1;min-width:0;margin:0;padding:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;display:block}
  .topbar-r{flex-shrink:0;display:flex;align-items:center}
  .topbar-r a{color:#666;margin-left:16px;display:inline-block}
  .topbar-r a:first-child{margin-left:0}
  .topbar a:hover{color:#c81623}

  /* 头部 */
  .header{background:#fff;box-shadow:0 2px 6px rgba(0,0,0,.04);position:sticky;top:0;z-index:999}
  .header .wrap{display:flex;justify-content:space-between;align-items:center;padding:16px 0}
  .logo{display:flex;align-items:center}
  .logo img{height:48px;width:auto;display:block}
  .nav ul{display:flex;gap:34px}
  .nav a{font-size:16px;color:#333;font-weight:500}
  .nav a.active,.nav a:hover{color:#c81623}
  .nav ul li a svg,.nav ul li a .arrow{display:none}
  .drawer-head,.drawer-foot{display:none}
  .menu-btn{display:none;font-size:26px;cursor:pointer}

  /* Banner */
  .banner{position:relative;width:100%;overflow:hidden;background:#222}
  .banner .bg{width:100%;height:460px;background:
    linear-gradient(135deg,rgba(0,0,0),rgba(60,10,10,.85)),
    url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='1600' height='460'><rect width='1600' height='460' fill='%231a1a1a'/><circle cx='200' cy='400' r='180' fill='%23c81623' opacity='.25'/><circle cx='1400' cy='100' r='220' fill='%23c81623' opacity='.18'/></svg>") center/cover no-repeat;display:flex;align-items:center;justify-content:center}
  .banner .txt{text-align:center;color:#fff}
  .banner h1{font-size:46px;letter-spacing:4px;margin-bottom:14px}
  .banner h1 span{color:#c81623}
  .banner p{font-size:16px;color:#ddd;margin-bottom:28px}
  .banner .btns{display:flex;gap:16px;justify-content:center}
  .btn{display:inline-block;padding:12px 32px;border:1px solid #c81623;color:#c81623;border-radius:2px;font-size:15px;transition:.3s}
  .btn:hover{background:#c81623;color:#fff}
  .btn.primary{background:#c81623;color:#fff}
  .btn.primary:hover{background:#a7121d}

  /* 板块标题 */
  .section{padding:28px 0}
  .sec-head{text-align:center;margin-bottom:32px}
  .sec-head .sec-title{font-size:30px;color:#222;letter-spacing:2px;margin:0;display:block;line-height:1.3}
  .sec-head .sec-title a{color:#222;transition:.3s}
  .sec-head .sec-title a:hover{color:#c81623}
  .sec-head .sec-sub{color:#888;margin-top:10px;font-size:14px;display:block;line-height:1.6}

  /* 产品中心：电脑端一排四个，手机端两个两列 */
  .product-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}
  .pro-card{border:1px solid #eee;background:#fff;border-radius:4px;overflow:hidden;transition:.3s;display:flex;flex-direction:column}
  .pro-card:hover{transform:translateY(-4px);box-shadow:0 10px 24px rgba(0,0,0,.08);border-color:#c81623}
  .pro-card .pic{height:240px;background:#f5f5f5;display:flex;align-items:center;justify-content:center;overflow:hidden;flex-shrink:0}
  .pro-card .pic img{width:100%;height:100%;object-fit:contain;display:block}
  .pro-card .pic svg{max-width:90%;max-height:90%;width:auto;height:auto}
  .pro-card .pic .no-thumb{color:#bbb;font-size:14px;padding:0 12px;text-align:center}
  .pro-card .info{padding:18px;text-align:center;flex:1}
  .pro-card h3{font-size:16px;color:#333;margin-bottom:8px;font-weight:600;line-height:1.4}
  .pro-card .price{color:#c81623;font-size:15px;font-weight:bold}

  /* 新闻：电脑端一排三列，手机1列 */
  .news-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
  .news-card{background:#fff;border:1px solid #eee;border-radius:4px;overflow:hidden;transition:.3s}
  .news-card:hover{box-shadow:0 10px 24px rgba(0,0,0,.08)}
  .news-card .pic{height:200px;background:#eee;display:flex;align-items:center;justify-content:center}
  .news-card .pic svg{width:80%;height:80%}
  .news-card .info{padding:20px}
  .news-card .tag{display:inline-block;padding:2px 10px;background:#c81623;color:#fff;font-size:12px;border-radius:2px;margin-bottom:10px}
  .news-card h3{font-size:18px;margin-bottom:12px;color:#222;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
  .news-card p{color:#666;font-size:14px;margin-bottom:10px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;height:42px}
  .news-card .date{color:#999;font-size:13px}

  /* 底部：黑色 */
  .footer{
    background:
      linear-gradient(180deg,#232426,#0f1012),
      url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='1600' height='400'><defs><pattern id='p' width='60' height='60' patternUnits='userSpaceOnUse'><circle cx='30' cy='30' r='1' fill='%23c81623' opacity='.15'/></pattern></defs><rect width='1600' height='400' fill='%23111'/><rect width='1600' height='400' fill='url(%23p)'/></svg>") center/cover no-repeat,
      #111;
    color:#ccc;
    padding-top:60px;
    position:relative;
    margin-bottom:0 !important; /* 清除footer默认下边距 */
  }
  .footer::before{content:"";position:absolute;left:0;top:0;width:100%;height:4px;background:linear-gradient(90deg,#c81623,#770000,#c81623)}
  .footer .grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:30px;padding-bottom:40px;border-bottom:1px solid rgba(255,255,255,.06)}
  .footer h4{color:#fff;font-size:16px;margin-bottom:18px;letter-spacing:1px}
  .footer p,.footer a{color:#bbb;font-size:14px;line-height:2}
  .footer a:hover{color:#c81623}
  .footer .logo-foot{display:flex;align-items:center;margin-bottom:16px}
  .footer .logo-foot img{height:56px;width:auto}
  .footer .desc{color:#999;font-size:13px;line-height:1.9}

  /* 联系我们【电脑端】热线一行、邮箱一行（邮箱换行），行间无空格 */
  .contact-info{display:flex;flex-direction:column;gap:0px;}
  .contact-info .row{display:flex;flex-direction:column;gap:0}

  /* 社交图标：方形 */
  .social{display:flex;gap:12px;margin-top:18px}
  .social a{width:44px;height:44px;background:#2a2b2d;border:1px solid #3a3b3d;border-radius:2px;display:flex;align-items:center;justify-content:center;color:#fff;font-size:13px;transition:.3s}
  .social a:hover{background:#c81623;border-color:#c81623;transform:translateY(-3px)}
  .social a svg{width:60%;height:60%;fill:#fff}

  .copy{text-align:center;padding:24px 0;color:#777;font-size:13px;border-top:1px solid rgba(255,255,255,.06)}
  .copy a{color:#777}
  .copy a:hover{color:#c81623}

  /* 手机底部固定四键导航：黑色背景 */
  .mobile-nav{display:none;position:fixed;bottom:0;left:0;width:100%;height:64px;background:#111;border-top:1px solid #c81623;z-index:998;grid-template-columns:repeat(4,1fr);
    /* 适配iphone底部小黑条 */
    padding-bottom: env(safe-area-inset-bottom,0);
  }
  .mobile-nav a{display:flex;flex-direction:column;align-items:center;justify-content:center;font-size:12px;color:#ccc;gap:4px}
  .mobile-nav a:hover,.mobile-nav a.active{color:#c81623}
  .mobile-nav svg{width:22px;height:22px;fill:#ccc}
  .mobile-nav a:hover svg,.mobile-nav a.active svg{fill:#c81623}

  /* 响应式 */
  @media(max-width:960px){
    .product-grid{grid-template-columns:repeat(2,1fr)}
    .footer .grid{grid-template-columns:1fr 1fr}
    .banner .bg{height:340px}
    .banner h1{font-size:32px}
  }
  @media(max-width:768px){
    /* 手机端顶部优化 */
    .topbar .topbar-in{font-size:11px;flex-wrap:nowrap;gap:0;padding:6px 0}
    .topbar p{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;margin:0;padding:0}
    .topbar .topbar-r{display:flex;align-items:center}
    .topbar .topbar-r a{margin-left:10px;font-size:11px}
    .topbar .topbar-r a:first-child{margin-left:0}
    .header .wrap{padding:12px 0}
    .logo img{height:38px}
    /* 仅手机端添加底部内边距，给固定导航留出位置，电脑端不再留白 */
    body{padding-bottom:calc(64px + env(safe-area-inset-bottom, 0px));}

    .nav{position:fixed;top:0;right:-100%;width:78%;max-width:330px;height:100vh;height:100dvh;background:#fff;box-shadow:0 0 24px rgba(0,0,0,.18);transition:right .32s ease;z-index:1001;display:flex;flex-direction:column;overflow-y:auto;padding:0}
    .nav.open{right:0}
    .drawer-head{display:flex;align-items:center;justify-content:space-between;padding:20px 22px;background:linear-gradient(135deg,#d9202e,#8a0f18)}
    .drawer-brand{display:flex;flex-direction:column;gap:2px}
    .drawer-brand .cn{font-size:18px;font-weight:700;color:#fff;letter-spacing:2px}
    .drawer-brand .en{font-size:11px;color:rgba(255,255,255,.75);letter-spacing:1px}
    .drawer-close{width:32px;height:32px;border:1px solid rgba(255,255,255,.5);border-radius:50%;color:#fff;font-size:14px;line-height:30px;text-align:center;cursor:pointer;flex-shrink:0}
    .nav ul{display:flex;flex-direction:column;gap:0;padding:10px 0;margin:0;flex:1}
    .nav ul li{border-bottom:1px solid #f3f3f3}
    .nav ul li a{display:flex;align-items:center;gap:14px;padding:15px 22px;font-size:15px;color:#333;border-left:3px solid transparent;transition:.25s}
    .nav ul li a svg{width:20px;height:20px;fill:#999;flex-shrink:0;transition:.25s;display:block}
    .nav ul li a span{flex:1}
    .nav ul li a .arrow{font-size:14px;color:#ccc;display:block}
    .nav ul li a:hover{background:#fdf2f2;color:#c81623}
    .nav ul li a:hover svg{fill:#c81623}
    .nav ul li a.active{background:#fdf2f2;color:#c81623;border-left-color:#c81623;font-weight:600}
    .nav ul li a.active svg{fill:#c81623}
    .drawer-foot{display:block;padding:18px 22px 26px;border-top:1px solid #f0f0f0}
    .drawer-foot p{font-size:13px;color:#888;margin-bottom:12px}
    .drawer-foot p b{color:#c81623;font-size:15px;font-weight:600}
    .drawer-social{display:flex;gap:10px}
    .drawer-social a{width:34px;height:34px;border-radius:6px;background:#f5f5f5;display:flex;align-items:center;justify-content:center;transition:.25s}
    .drawer-social a svg{width:18px;height:18px;fill:#666;transition:.25s}
    .drawer-social a:hover{background:#c81623}
    .drawer-social a:hover svg{fill:#fff}
    .menu-btn{display:block;z-index:1002}
    .nav-mask{display:none;position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,.45);z-index:1000}
    .nav-mask.show{display:block}
    /* 手机端产品一排两列，只显示前两个 */
    .product-grid{grid-template-columns:repeat(2,1fr)}
    .pro-card:nth-child(n+3){display:none}
    /* 手机新闻1列，且只显示第一条 */
    .news-grid{grid-template-columns:1fr}
    .news-card:nth-child(n+2){display:none}
    /* 手机footer压矮 */
    .footer{padding-top:36px}
    .footer .grid{
      grid-template-columns:1fr;
      gap:18px;
      padding-bottom:28px
    }
    /* 手机端隐藏快速导航、关于我们 */
    .footer .grid > div:nth-child(2),
    .footer .grid > div:nth-child(3){
      display:none
    }
    /* 手机端品牌介绍两行 */
    .footer .grid > div:first-child{
      text-align:center
    }
    .footer .logo-foot{
      justify-content:center
    }
    .footer .desc{
      display:-webkit-box;
      -webkit-line-clamp:2;
      -webkit-box-orient:vertical;
      overflow:hidden;
      text-align:center
    }
    /* =====手机端：热线邮箱一行（带间隔），地址单独一行===== */
    .contact-info{
      flex-direction:column;
      align-items:center;
      gap:6px;
    }
    .contact-info .row{
      flex-direction:row;
      flex-wrap:wrap;
      justify-content:center;
      gap:0 16px; /* 号码与邮箱间隔16px */
    }
    /* 手机底部固定导航显示 */
    .mobile-nav{display:grid}
    .banner h1{font-size:26px}
  }