:root{
      --theme:#0B3D91;
      --theme-dark:#082b67;
      --ink:#172033;
      --muted:#6c778b;
      --line:#e5eaf2;
      --bg:#f5f7fb;
      --white:#fff;
      --shadow:0 16px 45px rgba(18,40,80,.09);
      --radius:18px;
    }
    *{box-sizing:border-box}
    html{scroll-behavior:smooth}
    body{margin:0;color:var(--ink);background:var(--bg);font-family:"PingFang SC","Microsoft YaHei",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{background:#0d1b35;color:#dce7fb;font-size:13px}
    .topbar .container{min-height:36px;display:flex;align-items:center;justify-content:space-between;gap:20px}
    .topbar-links{display:flex;gap:20px}
    .topbar a{color:#dce7fb;transition:.2s}
    .topbar a:hover{color:#fff}

    .header{position:relative;z-index:20;background:#fff;border-bottom:1px solid var(--line)}
    .header-inner{height:76px;display:flex;align-items:center;gap:34px}
    .logo{display:flex;align-items:center;gap:10px;flex:0 0 auto;font-size:19px;font-weight:800;color:var(--theme)}
    .logo img{width:35px;height:35px;object-fit:contain}
    .main-nav{flex:1}
    .nav-list{display:flex;align-items:center;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:26px 14px;color:#33415a;font-size:15px;white-space:nowrap}
    .nav-link:hover{color:var(--theme)}
    .has-arrow:after{content:"⌄";font-size:14px;line-height:1;transform:translateY(-2px)}
    .dropdown-panel,.mega-menu{position:absolute;top:calc(100% + 1px);left:50%;transform:translateX(-50%) translateY(8px);width:300px;padding:20px;background:#fff;border:1px solid var(--line);border-radius:0 0 14px 14px;box-shadow:var(--shadow);opacity:0;visibility:hidden;transition:.2s;z-index:30}
    .mega-menu{width:620px}
    .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:translateX(-50%) translateY(0)}
    .dropdown-panel:before,.mega-menu:before{content:"";position:absolute;top:-12px;left:0;right:0;height:12px}
    .drop-title,.mega-title{margin:0 0 12px;color:var(--theme);font-weight:800;font-size:14px}
    .drop-list,.mega-links{display:grid;gap:8px}
    .drop-list a,.mega-links a{display:block;padding:6px 0;color:#48556b;font-size:13px;border-bottom:1px solid #f0f2f6}
    .drop-list a:hover,.mega-links a:hover{color:var(--theme)}
    .mega-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}
    .mega-card{display:flex;gap:9px;min-width:0;padding:10px;border:1px solid var(--line);border-radius:10px;background:#fbfcff}
    .mega-card:hover{border-color:#a8bfe7;background:#f3f7ff}
    .mega-card img{width:32px;height:32px;object-fit:contain;flex:0 0 32px}
    .mega-card span{min-width:0}
    .mega-card strong,.mega-card small{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
    .mega-card strong{font-size:13px;color:#24324b}
    .mega-card small{font-size:11px;color:var(--muted)}
    .mega-columns{display:grid;grid-template-columns:1fr 1fr;gap:28px}
    .mega-footer{display:block;margin-top:16px;padding-top:12px;border-top:1px solid var(--line);font-size:13px;color:var(--theme);font-weight:700}
    .header-btns{display:flex;align-items:center;gap:12px;flex:0 0 auto}
    .member-btn{padding:8px 14px;border-radius:8px;background:var(--theme);color:#fff;font-size:13px}
    .account-link{font-size:14px;color:var(--theme);font-weight:700}
    .hamburger{display:none;border:0;background:none;padding:7px;cursor:pointer}
    .hamburger span{display:block;width:24px;height:2px;margin:5px 0;background:#22314b;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(6,17,38,.52);opacity:0;visibility:hidden;transition:.25s;z-index:50}
    .drawer-overlay.open{opacity:1;visibility:visible}
    .mobile-drawer{position:fixed;top:0;right:0;bottom:0;width:min(390px,88vw);background:#fff;transform:translateX(100%);transition:.28s;z-index:60;overflow:auto}
    .mobile-drawer.open{transform:translateX(0)}
    .drawer-head{display:flex;align-items:center;gap:14px;padding:20px;border-bottom:1px solid var(--line);color:var(--theme)}
    .drawer-head strong{flex:1}
    .drawer-head a{font-size:14px}
    .drawer-close{border:0;background:none;font-size:30px;line-height:1;color:#657188;cursor:pointer}
    .drawer-menu{padding:10px 20px 30px}
    .drawer-link,.drawer-toggle{display:block;width:100%;padding:14px 0;border:0;border-bottom:1px solid #edf0f5;background:none;text-align:left;color:#25334b;font-size:15px;cursor:pointer}
    .drawer-toggle:after{content:"＋";float:right;color:#8a95a7}
    .drawer-toggle.active{color:var(--theme)}
    .drawer-toggle.active:after{content:"－"}
    .drawer-submenu{display:none;padding:4px 0 8px 15px}
    .drawer-submenu.open{display:block}
    .drawer-submenu a{display:block;padding:8px 0;color:#657188;font-size:14px}

    .product-page{padding:48px 0 70px}
    .breadcrumb{display:flex;align-items:center;gap:9px;margin-bottom:24px;color:#7c8799;font-size:13px}
    .breadcrumb a:hover{color:var(--theme)}
    .product-layout{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:28px;align-items:start}
    .product-main,.product-side{background:var(--white);border:1px solid var(--line);border-radius:var(--radius);box-shadow:0 8px 30px rgba(28,52,93,.05)}
    .product-main{padding:34px}
    .product-heading{display:grid;grid-template-columns:180px minmax(0,1fr);gap:28px;align-items:center;padding-bottom:28px;border-bottom:1px solid var(--line)}
    .product-cover{height:180px;border-radius:15px;background:#f2f6fc;display:flex;align-items:center;justify-content:center;padding:18px}
    .product-cover img{width:100%;height:100%;object-fit:contain}
    .product-kicker{display:inline-flex;padding:5px 10px;border-radius:999px;background:#edf3fc;color:var(--theme);font-size:12px;font-weight:700}
    .product-title{margin:12px 0 10px;font-size:32px;line-height:1.3;color:#172c52}
    .product-summary{margin:0;color:var(--muted);font-size:15px}
    .product-meta{display:flex;flex-wrap:wrap;gap:10px 20px;margin-top:18px;color:#738096;font-size:13px}
    .product-meta strong{color:#34435b}
    .product-body{min-width:0;max-width:100%;overflow-x:auto;padding-top:30px;color:#445168;font-size:15px}
    .product-body h2,.product-body h3{color:#192f55;line-height:1.4}
    .product-body h2{margin:26px 0 12px;font-size:22px}
    .product-body h3{margin:20px 0 8px;font-size:18px}
    .product-body p{margin:12px 0}
    .product-body img,.product-body table{max-width:100%;height:auto}
    .product-body table{border-collapse:collapse}
    .product-body td,.product-body th{padding:8px 12px;border:1px solid var(--line)}
    .product-body ul,.product-body ol{padding-left:24px}
    .product-side{padding:24px;position:sticky;top:20px}
    .side-title{margin:0 0 18px;padding-bottom:14px;border-bottom:1px solid var(--line);font-size:18px;color:#1d3154}
    .side-action{display:block;text-align:center;margin-bottom:22px;padding:12px 15px;border-radius:9px;background:var(--theme);color:#fff;font-weight:700}
    .side-action:hover{background:var(--theme-dark)}
    .side-facts{display:grid;gap:12px;margin-bottom:25px}
    .side-fact{display:flex;justify-content:space-between;gap:12px;color:#78849a;font-size:13px}
    .side-fact strong{color:#293a57;text-align:right}
    .related-products{display:grid;gap:11px}
    .related-product{display:grid;grid-template-columns:52px minmax(0,1fr);gap:11px;align-items:center;padding:10px;border:1px solid var(--line);border-radius:11px}
    .related-product:hover{border-color:#abc0e5}
    .related-product img{width:52px;height:52px;object-fit:contain;border-radius:8px;background:#f4f7fb}
    .related-product strong{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:14px;color:#263853}
    .related-product p{display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden;margin:3px 0 0;color:#7b8799;font-size:12px;line-height:1.5}

    .footer{background:#0d1b35;color:#c6d0e1;padding:52px 0 20px}
    .footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr 1.2fr;gap:38px}
    .footer h3{margin:0 0 14px;color:#fff;font-size:15px}
    .footer-brand strong{display:block;margin-bottom:13px;color:#fff;font-size:19px}
    .footer p{margin:7px 0;color:#aab6ca;font-size:13px}
    .footer-grid>div:not(.footer-brand) a{display:block;margin:7px 0;color:#aab6ca;font-size:13px}
    .footer-grid>div:not(.footer-brand) a:hover{color:#fff}
    .footer-bottom{display:flex;justify-content:space-between;gap:20px;margin-top:38px;padding-top:18px;border-top:1px solid rgba(255,255,255,.12);color:#8997ad;font-size:12px}

    @media (max-width:980px){
      .header-inner{gap:18px}
      .main-nav{display:none}
      .hamburger{display:block}
      .account-link{display:none}
      .product-layout{grid-template-columns:1fr}
      .product-side{position:static}
      .footer-grid{grid-template-columns:repeat(2,1fr)}
    }
    @media (max-width:640px){
      .container{width:min(100% - 28px,1180px)}
      .topbar .container{align-items:flex-start;flex-direction:column;padding:9px 0;gap:2px}
      .topbar-links{gap:12px;flex-wrap:wrap}
      .header-inner{height:66px}
      .logo span{font-size:16px}
      .member-btn{padding:7px 9px;font-size:12px}
      .product-page{padding:28px 0 48px}
      .product-main{padding:20px}
      .product-heading{grid-template-columns:1fr;gap:18px}
      .product-cover{height:150px}
      .product-title{font-size:25px}
      .product-side{padding:20px}
      .footer{padding-top:36px}
      .footer-grid{grid-template-columns:1fr 1fr;gap:25px 18px}
      .footer-brand{grid-column:1/-1}
      .footer-bottom{display:block}
      .footer-bottom span{display:block;margin-top:6px}
    }