:root{
  --blue:#0B3D91;
  --blue-dark:#082a63;
  --ink:#172033;
  --muted:#64748b;
  --line:#e3e8f0;
  --surface:#ffffff;
  --soft:#f4f7fb;
  --accent:#d6a84f;
  --shadow:0 18px 45px rgba(15,35,75,.10);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:#f5f7fb;color:var(--ink);font-family:"Microsoft YaHei","PingFang SC",Arial,sans-serif;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% - 40px));margin:0 auto}
.topbar{height:38px;background:#071a3d;color:#dbe7fb;font-size:13px}
.topbar .container{height:38px;display:flex;align-items:center;justify-content:space-between;gap:20px}
.topbar a{margin-left:18px;color:#dbe7fb}
.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;flex:0 0 auto;color:var(--blue);font-weight:800;font-size:20px;white-space:nowrap}
.logo img{width:38px;height:38px;object-fit:contain;border-radius:8px}
.main-nav{margin-left:auto}
.nav-list{display:flex;align-items:stretch;gap:3px;list-style:none;padding:0;margin:0}
.nav-item{position:relative}
.nav-link{display:flex;align-items:center;min-height:76px;padding:0 14px;color:#29364d;font-size:14px;font-weight:600;white-space:nowrap}
.nav-link:hover,.nav-link:focus{color:var(--blue)}
.has-arrow:after{content:"";width:6px;height:6px;margin:0 0 4px 8px;border-right:1.5px solid currentColor;border-bottom:1.5px solid currentColor;transform:rotate(45deg)}
.dropdown-panel,.mega-menu{position:absolute;top:calc(100% - 1px);left:50%;transform:translateX(-50%);visibility:hidden;opacity:0;pointer-events:none;background:#fff;border:1px solid var(--line);border-radius:0 0 14px 14px;box-shadow:var(--shadow);transition:.2s ease;z-index:30}
.dropdown-panel{width:260px;padding:10px}
.dropdown-panel a{display:block;padding:10px 12px;border-radius:8px;font-size:13px}
.dropdown-panel a:hover{background:var(--soft);color:var(--blue)}
.mega-menu{width:650px;padding:18px}
.nav-item:hover>.dropdown-panel,.nav-item:focus-within>.dropdown-panel,.nav-item:hover>.mega-menu,.nav-item:focus-within>.mega-menu{visibility:visible;opacity:1;pointer-events:auto}
.nav-item:hover>.dropdown-panel:before,.nav-item:hover>.mega-menu:before{content:"";position:absolute;left:0;right:0;top:-14px;height:14px}
.mega-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}
.mega-card{display:block;padding:12px;border:1px solid var(--line);border-radius:10px;background:#fff;transition:.2s}
.mega-card:hover{border-color:#a8bddf;transform:translateY(-2px)}
.mega-card img{width:42px;height:42px;object-fit:cover;border-radius:8px;margin-bottom:8px;background:#edf2fa}
.mega-card strong{display:block;font-size:14px;color:var(--ink);margin-bottom:4px}
.mega-card small{display:block;color:var(--muted);font-size:11px;line-height:1.55}
.mega-footer{display:inline-block;margin-top:14px;padding:7px 13px;color:var(--blue);font-size:13px;border-radius:7px;background:#edf3fc}
.mega-footer:hover{background:#dfeafb}
.product-menu{width:680px}
.product-menu .mega-grid+.mega-grid{grid-template-columns:repeat(4,1fr);margin-top:12px}
.product-menu .mega-grid+.mega-grid .mega-footer{margin:0;width:100%;text-align:center}
.header-btns{display:flex;align-items:center;gap:10px;white-space:nowrap}
.member-entry{font-size:13px;color:var(--blue);font-weight:700}
.open-account{padding:9px 15px;border-radius:7px;background:var(--blue);color:#fff;font-size:13px;font-weight:700}
.open-account:hover{background:var(--blue-dark)}
.hamburger{display:none;width:40px;height:40px;padding:8px;border:1px solid var(--line);border-radius:8px;background:#fff;cursor:pointer}
.hamburger span{display:block;height:2px;margin:5px 0;background:var(--blue);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{display:none;position:fixed;inset:0;background:rgba(4,14,33,.48);z-index:50}
.drawer-overlay.open{display:block}
.mobile-drawer{position:fixed;top:0;right:-360px;width:min(360px,88vw);height:100vh;overflow:auto;background:#fff;z-index:60;box-shadow:-15px 0 40px rgba(0,0,0,.18);transition:right .25s ease}
.mobile-drawer.open{right:0}
.drawer-head{display:flex;align-items:center;gap:12px;padding:20px;border-bottom:1px solid var(--line);color:var(--blue);font-weight:800}
.drawer-head a{margin-left:auto;padding:6px 10px;color:#fff;background:var(--blue);border-radius:6px;font-size:13px}
.drawer-close{border:0;background:transparent;color:#56657b;font-size:28px;line-height:1;cursor:pointer}
.drawer-menu{padding:10px 18px 30px}
.drawer-link,.drawer-toggle{display:block;width:100%;padding:14px 4px;border:0;border-bottom:1px solid #edf0f5;background:transparent;text-align:left;color:var(--ink);font-size:15px;cursor:pointer}
.drawer-toggle:after{content:"+";float:right;color:var(--blue);font-size:20px;line-height:1}
.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:8px 0;color:var(--muted);font-size:13px}
.footer{margin-top:70px;background:#0b1935;color:#c7d3e7}
.footer-grid{display:grid;grid-template-columns:1.35fr 1fr 1fr 1.15fr;gap:34px;padding:50px 0 38px}
.footer h3,.footer h4{margin:0 0 16px;color:#fff}
.footer h3{font-size:20px}
.footer h4{font-size:15px}
.footer p{margin:7px 0;color:#aebbd0;font-size:13px}
.footer-grid>div>a{display:block;margin:7px 0;color:#aebbd0;font-size:13px}
.footer-grid>div>a:hover{color:#fff}
.footer-bottom{display:flex;justify-content:space-between;gap:20px;padding:18px 0;border-top:1px solid rgba(255,255,255,.14);font-size:12px;color:#91a2bd}
.video-detail-main{padding:54px 0 10px}
.video-detail-main .video-breadcrumb{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-bottom:20px;color:var(--muted);font-size:13px}
.video-detail-main .video-breadcrumb a{color:var(--blue)}
.video-detail-main .video-heading{text-align:center;max-width:900px;margin:0 auto 30px}
.video-detail-main .video-heading h1{margin:0;color:var(--ink);font-size:clamp(28px,4vw,48px);line-height:1.25;letter-spacing:-.03em}
.video-detail-main .video-heading p{margin:16px 0 0;color:var(--muted);font-size:15px}
.video-player-shell{position:relative;width:100%;overflow:hidden;background:#08152e;border-radius:18px;box-shadow:0 22px 55px rgba(8,26,61,.18)}
.video-player-shell:before{content:"";display:block;padding-top:56.25%}
.video-player-shell .video-frame{position:absolute;inset:0;width:100%;height:100%;border:0}
.video-player-shell .player-fallback{position:absolute;inset:0;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:30px;text-align:center;color:#dbe7fb;background:linear-gradient(135deg,#071a3d,#173b76 55%,#0b3d91)}
.player-fallback .play-icon{display:grid;place-items:center;width:76px;height:76px;margin-bottom:15px;border:1px solid rgba(255,255,255,.45);border-radius:50%;font-size:30px;color:#fff}
.player-fallback strong{font-size:18px}
.player-fallback span{margin-top:6px;color:#aec1e0;font-size:13px}
.video-info-layout{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:30px;margin-top:32px}
.video-content-card,.video-side-card{background:#fff;border:1px solid var(--line);border-radius:14px;box-shadow:0 8px 24px rgba(18,39,77,.05)}
.video-content-card{padding:28px 32px;min-width:0}
.video-side-card{padding:22px}
.video-content-card h2,.video-side-card h2{margin:0 0 18px;color:var(--ink);font-size:20px}
.video-content{min-width:0;max-width:100%;overflow-x:auto;color:#46546a;font-size:15px}
.video-content img,.video-content table{max-width:100%}
.video-content table{display:block;overflow-x:auto}
.video-meta{display:flex;flex-wrap:wrap;gap:10px 20px;margin-bottom:22px;padding-bottom:18px;border-bottom:1px solid var(--line);color:var(--muted);font-size:13px}
.video-meta strong{color:var(--ink)}
.video-tags{display:flex;flex-wrap:wrap;gap:8px;margin-top:25px}
.video-tags a{padding:6px 11px;border-radius:20px;background:#eef3fb;color:var(--blue);font-size:12px}
.video-side-card .side-video{display:grid;grid-template-columns:92px minmax(0,1fr);gap:12px;padding:12px 0;border-bottom:1px solid var(--line)}
.video-side-card .side-video:last-child{border-bottom:0}
.side-video img{width:92px;height:62px;object-fit:cover;border-radius:7px;background:#e8eef7}
.side-video strong{display:-webkit-box;overflow:hidden;-webkit-line-clamp:2;-webkit-box-orient:vertical;font-size:13px;line-height:1.45}
.side-video small{display:block;margin-top:4px;color:var(--muted);font-size:11px}
.video-actions{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-top:28px;padding-top:22px;border-top:1px solid var(--line)}
.video-action-link{display:inline-flex;align-items:center;gap:7px;color:var(--blue);font-size:13px;font-weight:700}
.video-action-link:hover{text-decoration:underline}
@media (max-width:1050px){
  .main-nav{display:none}
  .hamburger{display:block}
  .header-btns{margin-left:auto}
  .member-entry{display:none}
}
@media (max-width:760px){
  .container{width:min(100% - 28px,1180px)}
  .topbar{height:auto;min-height:38px}
  .topbar .container{height:auto;min-height:38px;padding:8px 0;align-items:flex-start;flex-direction:column;gap:2px}
  .topbar a{margin-left:0;margin-right:15px}
  .header-inner{min-height:66px}
  .logo{font-size:17px}
  .logo img{width:32px;height:32px}
  .open-account{padding:8px 10px;font-size:12px}
  .video-detail-main{padding-top:34px}
  .video-detail-main .video-heading h1{font-size:30px}
  .video-info-layout{grid-template-columns:1fr;gap:20px}
  .video-content-card{padding:22px 18px}
  .video-side-card{padding:18px}
  .video-actions{align-items:flex-start;flex-direction:column}
  .footer{margin-top:45px}
  .footer-grid{grid-template-columns:1fr 1fr;gap:25px;padding:35px 0 28px}
  .footer-bottom{align-items:flex-start;flex-direction:column;gap:5px}
}
@media (max-width:480px){
  .header-btns{gap:6px}
  .footer-grid{grid-template-columns:1fr}
  .video-detail-main .video-heading h1{font-size:26px}
  .video-player-shell{border-radius:12px}
}