:root{
      --theme:#0B3D91;
      --ink:#172033;
      --muted:#6b7485;
      --paper:#f5f8fc;
      --line:#e4e9f1;
      --white:#fff;
      --shadow:0 18px 45px rgba(21,43,78,.10);
      --radius:14px;
    }
    *{box-sizing:border-box}
    html,body{margin:0;padding:0}
    body{font-family:"Microsoft YaHei","PingFang SC",Arial,sans-serif;color:var(--ink);background:var(--paper);line-height:1.7}
    a{color:inherit;text-decoration:none}
    img{max-width:100%;display:block}
    button{font:inherit}
    .container{width:min(1180px,calc(100% - 36px));margin:0 auto}
    .topbar{background:#102443;color:#dce7f8;font-size:13px}
    .topbar .container{min-height:38px;display:flex;align-items:center;justify-content:space-between;gap:20px}
    .topbar a{color:#fff}
    .header{position:relative;z-index:20;background:#fff;border-bottom:1px solid var(--line)}
    .header-inner{min-height:76px;display:flex;align-items:center;gap:30px}
    .logo{display:flex;align-items:center;gap:10px;min-width:190px;color:var(--theme);font-size:19px;font-weight:800}
    .logo img{width:38px;height:38px;object-fit:contain}
    .main-nav{flex:1}
    .nav-list{display:flex;align-items:stretch;justify-content:center;gap:4px;list-style:none;margin:0;padding:0}
    .nav-item{position:relative}
    .nav-link{display:flex;align-items:center;gap:5px;padding:25px 13px;color:#27344b;font-size:15px;white-space:nowrap}
    .nav-link:hover,.nav-link:focus{color:var(--theme)}
    .has-arrow:after{content:"";width:6px;height:6px;border-right:1px solid currentColor;border-bottom:1px solid currentColor;transform:rotate(45deg) translateY(-2px)}
    .dropdown-panel,.mega-menu{position:absolute;top:100%;left:50%;transform:translateX(-50%);width:300px;padding:20px;background:#fff;border:1px solid var(--line);border-radius:0 0 12px 12px;box-shadow:var(--shadow);opacity:0;visibility:hidden;transition:.2s;z-index:30}
    .mega-menu{width:650px}
    .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}
    .dropdown-panel:before,.mega-menu:before{content:"";position:absolute;left:0;right:0;height:10px;top:-10px}
    .menu-title{font-size:14px;color:var(--theme);font-weight:800;margin:0 0 12px}
    .menu-list{display:grid;gap:8px}
    .menu-list a{display:block;padding:5px 0;color:#3c4658;font-size:13px;border-bottom:1px solid #f0f2f6}
    .menu-list a:hover,.mega-card:hover{color:var(--theme)}
    .mega-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
    .mega-card{display:block;min-height:68px;padding:10px;border:1px solid var(--line);border-radius:9px;color:#354156;font-size:12px;overflow:hidden}
    .mega-card img{width:28px;height:28px;object-fit:contain;margin-bottom:5px}
    .mega-card b{font-size:13px}
    .mega-card small{color:var(--muted);font-size:11px}
    .mega-footer{display:block;margin-top:14px;padding-top:12px;border-top:1px solid var(--line);color:var(--theme);font-size:13px;font-weight:700}
    .header-btns{display:flex;align-items:center;gap:10px;white-space:nowrap}
    .member,.open-account{padding:8px 13px;border-radius:7px;font-size:13px}
    .member{color:var(--theme);border:1px solid #cbd8ec}
    .open-account{background:var(--theme);color:#fff}
    .hamburger{display:none;border:0;background:transparent;padding:8px;cursor:pointer}
    .hamburger span{display:block;width:23px;height:2px;background:var(--ink);margin:5px 0;transition:.2s}
    .hamburger.active span:nth-child(1){transform:translateY(7px) rotate(45deg)}
    .hamburger.active span:nth-child(2){opacity:0}
    .hamburger.active span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
    .drawer-overlay{position:fixed;inset:0;background:rgba(9,22,43,.48);opacity:0;visibility:hidden;transition:.25s;z-index:40}
    .drawer-overlay.open{opacity:1;visibility:visible}
    .mobile-drawer{position:fixed;top:0;right:0;bottom:0;width:min(360px,88vw);background:#fff;transform:translateX(100%);transition:.28s;z-index:41;overflow:auto;box-shadow:-12px 0 35px rgba(0,0,0,.16)}
    .mobile-drawer.open{transform:translateX(0)}
    .drawer-head{display:flex;align-items:center;gap:12px;padding:20px;border-bottom:1px solid var(--line);color:var(--theme);font-weight:800}
    .drawer-head span{flex:1}
    .drawer-head a{background:var(--theme);color:#fff;padding:5px 10px;border-radius:5px;font-size:13px}
    .drawer-close{border:0;background:transparent;color:#667085;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 #edf0f5;background:transparent;text-align:left;color:#26344b;font-size:15px;cursor:pointer}
    .drawer-group{border-bottom:1px solid #edf0f5}
    .drawer-toggle:after{content:"+";float:right;color:var(--theme);font-size:20px}
    .drawer-toggle.active:after{content:"−"}
    .drawer-submenu{display:none;padding:4px 0 9px 14px}
    .drawer-submenu.open{display:block}
    .drawer-submenu a{display:block;padding:7px 0;color:var(--muted);font-size:13px}
    .footer{margin-top:70px;background:#102443;color:#cad6e8}
    .footer-grid{display:grid;grid-template-columns:1.35fr 1fr 1fr 1fr;gap:38px;padding:48px 0 35px}
    .footer h3{margin:0 0 15px;color:#fff;font-size:16px}
    .footer p{margin:0 0 10px;font-size:13px;line-height:1.9}
    .footer a{display:block;color:#cad6e8;font-size:13px;margin:7px 0}
    .footer a:hover{color:#fff}
    .footer-bottom{padding:17px 0;border-top:1px solid rgba(255,255,255,.14);font-size:12px;color:#aebdd1}
    .video-detail-main{padding:42px 0 0}
    .video-detail-main .breadcrumb{color:var(--muted);font-size:13px;margin-bottom:22px}
    .video-detail-main .breadcrumb a{color:var(--theme)}
    .video-layout{display:grid;grid-template-columns:minmax(0,1fr) 290px;gap:28px;align-items:start}
    .video-article{background:#fff;border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);overflow:hidden}
    .video-heading{padding:30px 34px 18px;border-bottom:1px solid var(--line)}
    .video-heading h1{font-size:clamp(25px,3vw,38px);line-height:1.3;margin:0 0 15px;color:#142747}
    .video-meta{display:flex;flex-wrap:wrap;gap:13px 22px;color:var(--muted);font-size:13px}
    .player-wrap{padding:28px 34px 10px;background:#f8faff}
    .video-player{min-height:390px;display:flex;align-items:center;justify-content:center;background:#111d31;border-radius:10px;overflow:hidden;color:#fff}
    .video-player video,.video-player iframe{width:100%;min-height:390px;border:0}
    .video-placeholder{width:100%;min-height:390px;display:flex;align-items:center;justify-content:center;position:relative;background:linear-gradient(135deg,rgba(11,61,145,.88),rgba(13,27,52,.97)),url("{视频封面}") center/cover}
    .video-placeholder:after{content:"▶";display:grid;place-items:center;width:72px;height:72px;padding-left:5px;border:2px solid rgba(255,255,255,.8);border-radius:50%;font-size:28px;background:rgba(255,255,255,.12)}
    .video-body{padding:28px 34px 38px;min-width:0;max-width:100%;overflow-x:auto}
    .video-body h2{font-size:20px;margin:0 0 14px;color:#142747}
    .video-content{min-width:0;max-width:100%;overflow-x:auto;font-size:15px;color:#465268}
    .video-content img,.video-content table{max-width:100%}
    .video-tags{display:flex;flex-wrap:wrap;gap:8px;margin-top:25px;padding-top:18px;border-top:1px solid var(--line)}
    .video-tags span{padding:4px 10px;background:#edf3fc;color:var(--theme);border-radius:20px;font-size:12px}
    .video-side{display:grid;gap:18px}
    .side-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:0 8px 25px rgba(21,43,78,.06)}
    .side-card h2{font-size:17px;margin:0 0 15px;color:#142747}
    .side-card p{font-size:13px;color:var(--muted);margin:0 0 15px}
    .side-action{display:block;text-align:center;padding:10px;background:var(--theme);color:#fff;border-radius:7px;font-size:14px}
    .related-video{display:block;padding:12px 0;border-bottom:1px solid #edf0f5}
    .related-video:last-child{border-bottom:0}
    .related-video strong{display:block;font-size:13px;line-height:1.5}
    .related-video small{display:block;color:var(--muted);font-size:11px;margin-top:4px}
    @media(max-width:1050px){
      .nav-link{padding-left:8px;padding-right:8px}
      .logo{min-width:145px}
      .mega-menu{width:580px}
    }
    @media(max-width:820px){
      .main-nav{display:none}
      .hamburger{display:block}
      .member{display:none}
      .header-inner{min-height:68px}
      .logo{flex:1}
      .video-layout{grid-template-columns:1fr}
      .video-side{grid-template-columns:repeat(2,1fr)}
      .footer-grid{grid-template-columns:repeat(2,1fr)}
    }
    @media(max-width:560px){
      .container{width:min(100% - 26px,1180px)}
      .topbar .container{display:block;padding:8px 0;font-size:11px}
      .topbar .container span{display:block}
      .topbar .container span+span{margin-top:2px}
      .header-btns .open-account{display:none}
      .video-detail-main{padding-top:25px}
      .video-heading{padding:23px 19px 15px}
      .video-heading h1{font-size:25px}
      .player-wrap{padding:18px 14px 5px}
      .video-player,.video-placeholder,.video-player video,.video-player iframe{min-height:220px}
      .video-body{padding:22px 19px 28px}
      .video-side{grid-template-columns:1fr}
      .footer-grid{grid-template-columns:1fr;gap:25px;padding:35px 0 25px}
      .mega-grid{grid-template-columns:repeat(2,1fr)}
    }