:root{
      --theme:#0B3D91;
      --ink:#142033;
      --muted:#687386;
      --line:#e4e9f1;
      --soft:#f5f8fc;
      --white:#fff;
      --shadow:0 18px 45px rgba(22,42,75,.10);
      --radius:16px;
    }
    *{box-sizing:border-box}
    html{scroll-behavior:smooth}
    body{margin:0;background:#f7f9fc;color:var(--ink);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:#101a2b;color:#bfc9d9;font-size:13px}
    .topbar .container{min-height:38px;display:flex;align-items:center;justify-content:space-between;gap:20px}
    .topbar a{color:#e7edf7;margin-left:18px}
    .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;font-size:19px;font-weight:800;color:var(--ink);white-space:nowrap}
    .logo img{width:36px;height:36px;object-fit:contain}
    .main-nav{flex:1}
    .nav-list{display:flex;align-items:center;justify-content:center;gap:4px;list-style:none;padding:0;margin:0}
    .nav-item{position:relative}
    .nav-link{display:block;padding:25px 13px;font-size:14px;font-weight:600;color:#354154;white-space:nowrap}
    .nav-link:hover,.nav-item:focus-within>.nav-link{color:var(--theme)}
    .has-arrow:after{content:"⌄";font-size:12px;margin-left:6px;color:#8a95a5}
    .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 ease}
    .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;transform:translateX(-50%) translateY(0)}
    .dropdown-panel:before,.mega-menu:before{content:"";position:absolute;left:0;right:0;top:-12px;height:12px}
    .drop-title,.mega-title{font-size:14px;font-weight:800;color:var(--theme);margin-bottom:12px}
    .drop-list{display:grid;gap:8px}
    .drop-list a{font-size:13px;color:#445066;padding:5px 0;border-bottom:1px solid #f0f2f6}
    .drop-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:92px;padding:12px;border:1px solid var(--line);border-radius:10px;background:#fbfcfe}
    .mega-card img{width:27px;height:27px;object-fit:contain;margin-bottom:7px}
    .mega-card strong{display:block;font-size:13px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
    .mega-card small{display:block;font-size:11px;color:var(--muted);line-height:1.5;margin-top:3px}
    .mega-footer{display:block;margin-top:15px;padding-top:12px;border-top:1px solid var(--line);font-size:13px;font-weight:700;color:var(--theme)}
    .header-btns{display:flex;align-items:center;gap:9px;white-space:nowrap}
    .member-btn,.open-btn{padding:8px 13px;border-radius:8px;font-size:13px;font-weight:700}
    .member-btn{color:var(--theme);border:1px solid #cdd9ec}
    .open-btn{color:#fff;background:var(--theme)}
    .hamburger{display:none;width:42px;height:40px;border:1px solid var(--line);background:#fff;border-radius:8px;cursor:pointer}
    .hamburger span{display:block;width:20px;height:2px;margin:4px auto;background:#243249;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;background:rgba(7,17,33,.5);opacity:0;visibility:hidden;transition:.25s;z-index:40}
    .drawer-overlay.open{opacity:1;visibility:visible}
    .mobile-drawer{position:fixed;top:0;right:0;width:min(390px,88vw);height:100vh;background:#fff;z-index:41;transform:translateX(100%);transition:.28s;overflow:auto}
    .mobile-drawer.open{transform:translateX(0)}
    .drawer-head{display:flex;align-items:center;gap:15px;padding:20px;border-bottom:1px solid var(--line);font-weight:800}
    .drawer-head>a{margin-left:auto;color:var(--theme);font-size:14px}
    .drawer-close{width:32px;height:32px;border:0;background:#eef3fa;border-radius:50%;font-size:23px;line-height:1;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 var(--line);background:none;text-align:left;color:#263348;font-size:15px;cursor:pointer}
    .drawer-toggle:after{content:"＋";float:right;color:#8a95a5}
    .drawer-toggle.active:after{content:"－"}
    .drawer-submenu{display:none;padding:3px 0 8px 14px}
    .drawer-submenu.open{display:block}
    .drawer-submenu a{display:block;padding:8px 0;font-size:13px;color:var(--muted)}
    .footer{margin-top:70px;background:#101a2b;color:#c7d0df}
    .footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1.2fr;gap:38px;padding:48px 0 35px}
    .footer h3{margin:0 0 14px;color:#fff;font-size:15px}
    .footer a,.footer span{display:block;margin:7px 0;color:#aebacd;font-size:13px}
    .footer-brand strong{font-size:21px;color:#fff}
    .footer-brand p{max-width:330px;margin:10px 0;color:#aebacd;font-size:13px}
    .footer-bottom{display:flex;justify-content:space-between;gap:20px;padding:18px 0;border-top:1px solid rgba(255,255,255,.12);font-size:12px;color:#91a0b5}
    .tool-detail-page{padding:46px 0 0}
    .breadcrumb{font-size:13px;color:var(--muted);margin-bottom:25px}
    .breadcrumb a{color:var(--theme)}
    .tool-layout{display:grid;grid-template-columns:minmax(0,1fr) 320px;gap:28px;align-items:start}
    .tool-article,.related-tools{background:#fff;border:1px solid var(--line);border-radius:var(--radius);box-shadow:0 8px 28px rgba(22,42,75,.05)}
    .tool-article{padding:34px}
    .tool-kicker{display:inline-flex;align-items:center;gap:7px;padding:6px 11px;border-radius:999px;background:#edf3fc;color:var(--theme);font-size:12px;font-weight:700}
    .tool-title{margin:14px 0 8px;font-size:clamp(28px,4vw,44px);line-height:1.25;letter-spacing:-.03em}
    .tool-intro{margin:0 0 22px;color:var(--muted);font-size:16px}
    .tool-meta{display:flex;flex-wrap:wrap;gap:16px;padding:16px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line);color:var(--muted);font-size:13px}
    .tool-meta strong{color:var(--ink);font-weight:700}
    .tool-icon{width:76px;height:76px;padding:13px;object-fit:contain;border:1px solid var(--line);border-radius:16px;background:#f8faff}
    .tool-body{min-width:0;max-width:100%;overflow-x:auto;padding-top:26px;font-size:15px;color:#354154}
    .tool-body img,.tool-body video{max-width:100%;height:auto}
    .tool-body table{max-width:100%;display:block;overflow-x:auto;border-collapse:collapse}
    .tool-body h2,.tool-body h3{color:#17263d;line-height:1.4;margin:27px 0 12px}
    .tool-body h2{font-size:23px}
    .tool-body h3{font-size:18px}
    .tool-body p{margin:12px 0}
    .tool-body ul,.tool-body ol{padding-left:24px}
    .tool-body blockquote{margin:20px 0;padding:14px 18px;border-left:4px solid var(--theme);background:#f4f7fc;color:#536078}
    .related-tools{padding:22px;position:sticky;top:20px}
    .related-tools h2{margin:0 0 15px;font-size:18px}
    .related-tool-card{display:grid;grid-template-columns:48px 1fr;gap:11px;padding:14px 0;border-bottom:1px solid var(--line)}
    .related-tool-card:last-child{border-bottom:0}
    .related-tool-card img{width:48px;height:48px;padding:8px;border-radius:11px;background:#f4f7fc;border:1px solid var(--line);object-fit:contain}
    .related-tool-card strong{display:block;font-size:14px;line-height:1.4}
    .related-tool-card p{margin:4px 0 0;color:var(--muted);font-size:12px;line-height:1.5}
    .tool-actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:28px}
    .tool-actions a{padding:10px 17px;border-radius:8px;background:var(--theme);color:#fff;font-size:13px;font-weight:700}
    .tool-actions a.secondary{background:#edf3fc;color:var(--theme)}
    @media (max-width:980px){
      .main-nav{display:none}
      .header-btns .member-btn,.header-btns .open-btn{display:none}
      .hamburger{display:block}
      .tool-layout{grid-template-columns:1fr}
      .related-tools{position:static}
      .footer-grid{grid-template-columns:repeat(2,1fr)}
    }
    @media (max-width:620px){
      .container{width:min(100% - 28px,1180px)}
      .topbar .container{display:block;padding:8px 0}
      .topbar .container>span{display:block}
      .topbar a:first-child{margin-left:0}
      .header-inner{min-height:66px}
      .logo{font-size:16px}
      .logo img{width:31px;height:31px}
      .tool-detail-page{padding-top:28px}
      .tool-article{padding:22px 18px}
      .tool-title{font-size:30px}
      .footer-grid{grid-template-columns:1fr;gap:24px;padding:35px 0 25px}
      .footer-bottom{display:block}
      .footer-bottom span{display:block;margin:5px 0}
      .mega-grid{grid-template-columns:1fr}
    }