:root{
      --primary:#0B3D91;
      --primary-dark:#082b66;
      --ink:#172033;
      --muted:#697386;
      --line:#e4e8ef;
      --paper:#f6f8fb;
      --white:#fff;
      --accent:#d88a32;
      --shadow:0 18px 45px rgba(18,36,67,.10);
      --radius:8px
    }
    *{box-sizing:border-box}
    html{scroll-behavior:smooth}
    body{margin:0;color:var(--ink);background:var(--paper);font-family:"Microsoft YaHei","PingFang SC",Arial,sans-serif;line-height:1.7}
    a{color:inherit;text-decoration:none}
    img{display:block;max-width:100%}
    button{font:inherit}
    .container{width:min(1180px,calc(100% - 40px));margin:0 auto}

    .topbar{background:#101b30;color:#cdd6e5;font-size:13px}
    .topbar-inner{min-height:36px;display:flex;align-items:center;justify-content:space-between;gap:20px}
    .topbar-contact{display:flex;gap:22px}
    .topbar a:hover{color:#fff}

    .header{position:relative;z-index:20;background:var(--white);border-bottom:1px solid var(--line)}
    .header-inner{min-height:78px;display:flex;align-items:center;gap:28px}
    .logo{display:inline-flex;align-items:center;gap:10px;font-size:19px;font-weight:800;white-space:nowrap;color:var(--primary-dark)}
    .logo img{width:36px;height:36px;object-fit:contain}
    .main-nav{flex:1}
    .nav-list{display:flex;align-items:stretch;justify-content:center;gap:2px;padding:0;margin:0;list-style:none}
    .nav-item{position:relative}
    .nav-link{display:flex;align-items:center;min-height:78px;padding:0 13px;font-size:14px;white-space:nowrap}
    .nav-link:hover,.nav-link:focus-visible{color:var(--primary)}
    .has-arrow:after{content:"";width:6px;height:6px;margin:0 0 3px 8px;border-right:1px solid currentColor;border-bottom:1px solid currentColor;transform:rotate(45deg)}
    .header-btns{display:flex;align-items:center;gap:12px;white-space:nowrap}
    .header-btns>a:first-child{color:var(--primary);font-size:14px}
    .account-btn{padding:9px 16px;border-radius:5px;background:var(--primary);color:#fff;font-size:14px}
    .account-btn:hover{background:var(--primary-dark)}

    .dropdown-panel,.mega-menu{position:absolute;top:calc(100% + 1px);left:50%;z-index:30;width:260px;padding:18px;background:#fff;border:1px solid var(--line);box-shadow:var(--shadow);opacity:0;visibility:hidden;transform:translate(-50%,8px);transition:.2s ease}
    .mega-menu{width:680px}
    .mega-wide{width:min(900px,calc(100vw - 40px))}
    .nav-item:hover>.dropdown-panel,.nav-item:focus-within>.dropdown-panel,.nav-item:hover>.mega-menu,.nav-item:focus-within>.mega-menu{opacity:1;visibility:visible;transform:translate(-50%,0)}
    .dropdown-panel a{display:block;padding:8px 4px;border-bottom:1px solid var(--line);font-size:13px}
    .dropdown-panel a:hover{color:var(--primary)}
    .dropdown-all,.mega-footer{display:block;margin-top:14px;color:var(--primary);font-size:13px;font-weight:700}
    .mega-title{margin:0 0 12px;font-size:14px;color:var(--primary-dark)}
    .mega-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
    .mega-card{min-width:0;padding:10px;border:1px solid var(--line);border-radius:6px;background:#fbfcfe}
    .mega-card:hover{border-color:#a8bde0;background:#f4f7fc}
    .mega-card img{width:34px;height:34px;object-fit:contain;margin-bottom:7px}
    .mega-card .video-thumb,.mega-card .product-thumb{width:100%;height:68px;object-fit:cover}
    .mega-card strong{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:13px}
    .mega-card p{display:-webkit-box;overflow:hidden;margin:4px 0 0;color:var(--muted);font-size:11px;line-height:1.5;-webkit-box-orient:vertical;-webkit-line-clamp:2}
    .mega-meta{display:flex;justify-content:space-between;gap:8px;margin-top:5px;color:var(--muted);font-size:10px}
    .mega-columns{display:grid;grid-template-columns:150px 1fr;gap:18px}
    .mega-categories a{display:block;padding:5px 0;color:var(--muted);font-size:13px}
    .mega-categories a:hover{color:var(--primary)}

    .hamburger{display:none;width:42px;height:42px;padding:9px;border:1px solid var(--line);border-radius:5px;background:#fff;cursor:pointer}
    .hamburger span{display:block;width:22px;height:2px;margin:4px auto;background:var(--primary-dark);transition:.2s}
    .hamburger.active span:nth-child(1){transform:translateY(6px) rotate(45deg)}
    .hamburger.active span:nth-child(2){opacity:0}
    .hamburger.active span:nth-child(3){transform:translateY(-6px) rotate(-45deg)}

    .drawer-overlay{position:fixed;inset:0;z-index:40;background:rgba(5,14,30,.48);opacity:0;visibility:hidden;transition:.2s}
    .drawer-overlay.open{opacity:1;visibility:visible}
    .mobile-drawer{position:fixed;top:0;right:0;z-index:50;width:min(390px,88vw);height:100vh;overflow:auto;background:#fff;transform:translateX(100%);transition:.25s ease;box-shadow:-15px 0 35px rgba(0,0,0,.15)}
    .mobile-drawer.open{transform:translateX(0)}
    .drawer-head{display:flex;align-items:center;gap:14px;padding:20px;border-bottom:1px solid var(--line)}
    .drawer-head a{margin-left:auto;color:var(--primary);font-weight:700;font-size:14px}
    .drawer-close{width:34px;height:34px;border:0;background:transparent;color:var(--muted);font-size:28px;line-height:1;cursor:pointer}
    .drawer-menu{padding:10px 20px 30px}
    .drawer-link,.drawer-toggle{display:block;width:100%;padding:13px 0;border:0;border-bottom:1px solid var(--line);background:transparent;text-align:left;color:var(--ink);cursor:pointer;font-size:15px}
    .drawer-toggle:after{content:"+";float:right;color:var(--primary)}
    .drawer-toggle.active:after{content:"−"}
    .drawer-submenu{display:none;padding:5px 0 8px 14px}
    .drawer-submenu.open{display:block}
    .drawer-submenu a{display:block;padding:7px 0;color:var(--muted);font-size:14px}

    .video-page{padding:62px 0 80px}
    .page-heading{max-width:760px;margin:0 auto 38px;text-align:center}
    .eyebrow{margin:0 0 8px;color:var(--accent);font-size:13px;font-weight:800;letter-spacing:2px}
    .page-heading h1{margin:0;color:var(--primary-dark);font-size:clamp(30px,4vw,46px);line-height:1.25}
    .page-heading p{margin:14px 0 0;color:var(--muted);font-size:16px}
    .video-toolbar{display:flex;align-items:center;justify-content:space-between;gap:18px;margin-bottom:22px;padding-bottom:16px;border-bottom:1px solid var(--line)}
    .video-toolbar strong{font-size:18px;color:var(--primary-dark)}
    .category-links{display:flex;flex-wrap:wrap;gap:8px}
    .category-links a{padding:5px 12px;border:1px solid #cbd5e5;border-radius:30px;background:#fff;color:var(--muted);font-size:13px}
    .category-links a:hover{border-color:var(--primary);color:var(--primary)}
    .video-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
    .video-card{overflow:hidden;border:1px solid var(--line);border-radius:var(--radius);background:#fff;box-shadow:0 8px 25px rgba(31,55,92,.05);transition:.2s}
    .video-card:hover{transform:translateY(-4px);box-shadow:var(--shadow)}
    .video-cover{position:relative;aspect-ratio:16/9;overflow:hidden;background:#dfe7f1}
    .video-cover img{width:100%;height:100%;object-fit:cover}
    .video-duration{position:absolute;right:10px;bottom:10px;padding:2px 7px;border-radius:3px;background:rgba(11,22,42,.82);color:#fff;font-size:12px}
    .video-card-body{padding:18px}
    .video-card h2{margin:0 0 8px;color:var(--primary-dark);font-size:18px;line-height:1.4}
    .video-card h2 a:hover{color:var(--primary)}
    .video-summary{display:-webkit-box;min-height:50px;margin:0;color:var(--muted);font-size:14px;line-height:1.75;overflow:hidden;-webkit-box-orient:vertical;-webkit-line-clamp:2}
    .video-meta{display:flex;justify-content:space-between;gap:10px;margin-top:14px;padding-top:12px;border-top:1px solid var(--line);color:#8993a5;font-size:12px}
    .pagination{display:flex;justify-content:center;flex-wrap:wrap;gap:8px;margin-top:40px}
    .pagination a{min-width:34px;padding:5px 10px;border:1px solid var(--line);border-radius:4px;background:#fff;text-align:center;color:var(--muted);font-size:13px}
    .pagination a:hover,.pagination a.active{border-color:var(--primary);background:var(--primary);color:#fff}

    .footer{background:#101b30;color:#cdd6e5}
    .footer-main{display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:42px;padding:52px 0 38px}
    .footer .logo{color:#fff}
    .footer-brand p{margin:14px 0 0;color:#9eabc0;font-size:13px}
    .footer h3{margin:3px 0 16px;color:#fff;font-size:15px}
    .footer-links{display:grid;gap:8px}
    .footer-links a,.footer-contact p{color:#9eabc0;font-size:13px}
    .footer-links a:hover,.footer-contact a:hover{color:#fff}
    .footer-contact p{margin:8px 0}
    .footer-bottom{display:flex;justify-content:space-between;gap:20px;padding:18px 0;border-top:1px solid rgba(255,255,255,.12);color:#8795aa;font-size:12px}

    @media(max-width:1050px){
      .header-inner{gap:15px}
      .nav-link{padding:0 8px}
      .header-btns>a:first-child{display:none}
      .footer-main{grid-template-columns:repeat(2,1fr)}
    }
    @media(max-width:820px){
      .container{width:min(100% - 28px,620px)}
      .topbar-inner{align-items:flex-start;flex-direction:column;gap:0;padding:7px 0}
      .topbar-contact{gap:14px}
      .main-nav{display:none}
      .hamburger{display:block}
      .video-page{padding:42px 0 60px}
      .video-toolbar{align-items:flex-start;flex-direction:column}
      .video-grid{grid-template-columns:repeat(2,1fr);gap:16px}
      .footer-main{gap:28px}
      .footer-bottom{align-items:flex-start;flex-direction:column}
    }
    @media(max-width:560px){
      .header-inner{min-height:68px}
      .logo{font-size:17px}
      .logo img{width:32px;height:32px}
      .page-heading h1{font-size:31px}
      .page-heading p{font-size:14px}
      .video-grid{grid-template-columns:1fr}
      .footer-main{grid-template-columns:1fr;padding:38px 0 28px}
    }