:root{
      --theme:#0B3D91;
      --ink:#101827;
      --muted:#66758a;
      --line:#e4eaf2;
      --soft:#f4f7fb;
      --white:#fff;
      --accent:#18b6c9;
      --shadow:0 18px 50px rgba(16,34,63,.1);
    }
    *{box-sizing:border-box}
    html,body{margin:0;padding:0}
    body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei",Arial,sans-serif;color:var(--ink);background:#f7f9fc;line-height:1.7}
    a{color:inherit;text-decoration:none}
    img{max-width:100%;display:block}
    .container{width:min(1180px,calc(100% - 40px));margin:0 auto}
    .topbar{height:36px;background:#071b3d;color:#b9c8df;font-size:12px}
    .topbar-inner{height:36px;display:flex;align-items:center;justify-content:space-between}
    .topbar-links{display:flex;gap:22px}
    .topbar a:hover{color:#fff}
    .header{height:76px;background:#fff;border-bottom:1px solid var(--line);position:relative;z-index:20}
    .header-inner{height:76px;display:flex;align-items:center;gap:36px}
    .logo{display:flex;align-items:center;gap:10px;min-width:190px;font-weight:800;color:var(--theme);font-size:18px}
    .logo img{width:34px;height:34px;object-fit:contain}
    .main-nav{flex:1}
    .nav-list{display:flex;align-items:stretch;gap:3px;list-style:none;margin:0;padding:0}
    .nav-item{position:relative}
    .nav-link{display:flex;align-items:center;height:76px;padding:0 14px;font-size:14px;color:#26364d;white-space:nowrap}
    .nav-link:hover,.nav-item:focus-within>.nav-link{color:var(--theme)}
    .has-arrow:after{content:"⌄";font-size:13px;margin-left:7px;color:#8b99ab}
    .dropdown-panel,.mega-menu{position:absolute;top:100%;left:50%;transform:translateX(-50%);background:#fff;border:1px solid var(--line);box-shadow:var(--shadow);border-radius:0 0 14px 14px;opacity:0;visibility:hidden;pointer-events:none;transition:.2s;padding:20px;z-index:30}
    .dropdown-panel{width:280px}
    .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;pointer-events:auto}
    .dropdown-title,.mega-heading{font-size:13px;font-weight:800;color:var(--theme);margin-bottom:11px}
    .dropdown-panel>a{display:block;border-bottom:1px solid var(--line);padding:8px 0;font-size:13px}
    .dropdown-panel>a:last-child{border:0;color:var(--theme);font-weight:700}
    .mega-grid{display:grid;grid-template-columns:1fr 1fr;gap:28px}
    .mega-list{display:grid;gap:8px}
    .mega-list>a{display:flex;gap:9px;align-items:center;padding:6px;border-radius:8px}
    .mega-list>a:hover{background:var(--soft)}
    .mega-list img{width:32px;height:32px;object-fit:cover;border-radius:6px;background:#edf2f7}
    .mega-item-title,.mega-item-meta{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
    .mega-item-title{font-size:13px;font-weight:700}
    .mega-item-meta{font-size:11px;color:var(--muted);max-width:235px}
    .mega-categories{display:flex;flex-wrap:wrap;gap:8px}
    .mega-categories a,.mega-tools span{font-size:12px;color:#38516f;background:#f1f5fa;border-radius:20px;padding:5px 10px}
    .mega-tools{display:flex;flex-wrap:wrap;gap:7px;margin:14px 0}
    .mega-footer{display:inline-block;color:var(--theme);font-size:13px;font-weight:700;margin-top:12px}
    .header-btns{display:flex;align-items:center;gap:12px}
    .member-link{font-size:13px;color:var(--theme);font-weight:700}
    .account-btn{background:var(--theme);color:#fff;border-radius:8px;padding:8px 14px;font-size:13px}
    .hamburger{display:none;border:0;background:transparent;width:38px;height:38px;padding:8px;cursor:pointer}
    .hamburger span{height:2px;background:var(--theme);display:block;margin:5px 0;transition:.2s}
    .drawer-overlay{display:none}
    .mobile-drawer{display:none}
    .tool-detail-page{padding:54px 0 80px}
    .breadcrumbs{font-size:13px;color:var(--muted);margin-bottom:22px}
    .breadcrumbs a{color:var(--theme)}
    .tool-layout{display:grid;grid-template-columns:minmax(0,1fr) 310px;gap:30px;align-items:start}
    .tool-main,.tool-side{background:#fff;border:1px solid var(--line);border-radius:18px;box-shadow:0 10px 30px rgba(20,46,82,.05)}
    .tool-main{padding:34px}
    .tool-head{display:flex;gap:20px;align-items:flex-start;padding-bottom:25px;border-bottom:1px solid var(--line)}
    .tool-icon{width:74px;height:74px;object-fit:contain;border-radius:16px;background:#edf4ff;padding:12px;flex:0 0 auto}
    .tool-kicker{color:var(--theme);font-size:12px;font-weight:800;letter-spacing:.08em;margin:0 0 5px}
    .tool-head h1{font-size:32px;line-height:1.25;margin:0 0 9px}
    .tool-intro{color:var(--muted);margin:0;font-size:15px}
    .tool-meta{display:flex;gap:18px;flex-wrap:wrap;color:#718096;font-size:12px;margin-top:18px}
    .tool-meta strong{color:var(--ink);font-weight:700}
    .tool-body{min-width:0;max-width:100%;overflow-x:auto;padding-top:28px;font-size:15px}
    .tool-body img,.tool-body table{max-width:100%}
    .tool-body h2,.tool-body h3{color:#102b55;margin-top:28px}
    .tool-body blockquote{border-left:4px solid var(--accent);background:#f1fbfc;margin:22px 0;padding:13px 18px;color:#3d536e}
    .tool-body a{color:var(--theme);text-decoration:underline}
    .tool-side{padding:22px;position:sticky;top:20px}
    .side-title{font-size:17px;margin:0 0 16px}
    .related-tool{display:grid;grid-template-columns:48px 1fr;gap:11px;padding:13px 0;border-top:1px solid var(--line)}
    .related-tool img{width:48px;height:48px;border-radius:10px;object-fit:contain;background:#eff4fa;padding:7px}
    .related-tool h3{font-size:14px;margin:0 0 3px}
    .related-tool p{font-size:12px;line-height:1.45;color:var(--muted);margin:0;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
    .side-link{display:block;text-align:center;color:var(--theme);font-weight:700;font-size:13px;background:#edf4ff;border-radius:8px;padding:9px;margin-top:16px}
    .footer{background:#071b3d;color:#c0cee1;padding:48px 0 20px}
    .footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:35px}
    .footer-brand img{width:38px;height:38px;object-fit:contain;margin-bottom:10px}
    .footer h3{color:#fff;font-size:18px;margin:0 0 9px}
    .footer h4{color:#fff;font-size:14px;margin:5px 0 15px}
    .footer p,.footer a,.footer-contact span{font-size:12px;line-height:1.8}
    .footer p{margin:0;color:#aabbd2}
    .footer-links,.footer-contact{display:grid;gap:5px}
    .footer a:hover{color:#fff}
    .footer-bottom{border-top:1px solid rgba(255,255,255,.14);margin-top:35px;padding-top:18px;display:flex;justify-content:space-between;gap:20px;font-size:11px;color:#91a6c2}
    @media(max-width:980px){
      .main-nav{display:none}
      .header-inner{gap:15px}
      .header-btns{margin-left:auto}
      .hamburger{display:block}
      .mega-menu{display:none}
      .tool-layout{grid-template-columns:1fr}
      .tool-side{position:static}
    }
    @media(max-width:680px){
      .container{width:min(100% - 28px,1180px)}
      .topbar{height:auto;padding:7px 0}
      .topbar-inner{height:auto;display:block}
      .topbar-links{gap:12px;margin-top:2px}
      .topbar-links a{font-size:11px}
      .logo{min-width:0;font-size:16px}
      .member-link{display:none}
      .account-btn{font-size:12px;padding:7px 10px}
      .mobile-drawer{display:block;position:fixed;z-index:60;top:0;right:0;width:min(350px,88vw);height:100vh;background:#fff;transform:translateX(105%);transition:.25s;overflow:auto;box-shadow:-15px 0 40px rgba(0,0,0,.16)}
      .mobile-drawer.open{transform:translateX(0)}
      .drawer-overlay{display:block;position:fixed;inset:0;background:rgba(2,13,31,.55);opacity:0;visibility:hidden;z-index:50;transition:.25s}
      .drawer-overlay.open{opacity:1;visibility:visible}
      .drawer-head{height:70px;background:#071b3d;color:#fff;display:flex;align-items:center;gap:15px;padding:0 18px}
      .drawer-head span{font-weight:700;flex:1}
      .drawer-head a{background:#18b6c9;color:#071b3d;border-radius:6px;padding:4px 10px;font-size:12px;font-weight:700}
      .drawer-close{background:transparent;border:0;color:#fff;font-size:28px;cursor:pointer}
      .drawer-menu{padding:15px 18px}
      .drawer-link,.drawer-toggle{display:block;width:100%;padding:13px 0;border:0;border-bottom:1px solid var(--line);background:none;text-align:left;font:inherit;font-size:14px;color:var(--ink);cursor:pointer}
      .drawer-toggle:after{content:"＋";float:right;color:var(--theme)}
      .drawer-toggle.active:after{content:"－"}
      .drawer-submenu{display:none;padding:5px 0 8px 15px}
      .drawer-submenu.open{display:block}
      .drawer-submenu a{display:block;padding:8px 0;color:var(--muted);font-size:13px}
      .tool-detail-page{padding:30px 0 55px}
      .tool-main{padding:22px 18px}
      .tool-head h1{font-size:25px}
      .tool-icon{width:58px;height:58px}
      .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}
    }