:root{
      --theme:#0B3D91;
      --theme-deep:#08295f;
      --ink:#14213d;
      --muted:#64748b;
      --line:#dbe4f0;
      --bg:#f4f7fb;
      --card:#ffffff;
      --accent:#28d7a1;
      --shadow:0 18px 48px rgba(15,39,82,.10);
      --radius:18px;
    }
    *{box-sizing:border-box}
    html{scroll-behavior:smooth}
    body{margin:0;background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","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:#071d43;color:#c9d8ef;font-size:13px}
    .topbar .container{height:100%;display:flex;align-items:center;justify-content:space-between;gap:20px}
    .topbar strong{color:#fff;font-weight:700}
    .topbar a{margin-left:22px;color:#c9d8ef;transition:color .2s}
    .topbar a:hover{color:#fff}

    .header{position:relative;z-index:20;background:#fff;border-bottom:1px solid #e7edf5}
    .header-inner{min-height:76px;display:flex;align-items:center;gap:34px}
    .logo{display:flex;align-items:center;gap:11px;color:var(--theme);font-size:20px;font-weight:800;white-space:nowrap}
    .logo img{width:34px;height:34px;object-fit:contain}
    .main-nav{margin-left:auto}
    .nav-list{display:flex;align-items:stretch;gap:4px;list-style:none;margin:0;padding:0}
    .nav-item{position:relative}
    .nav-link{display:flex;align-items:center;min-height:76px;padding:0 14px;font-size:15px;color:#334155;white-space:nowrap}
    .nav-link:hover,.nav-link:focus{color:var(--theme)}
    .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:100%;left:50%;transform:translate(-50%,10px);width:260px;padding:16px;background:#fff;border:1px solid #e3eaf4;border-radius:0 0 15px 15px;box-shadow:var(--shadow);opacity:0;visibility:hidden;transition:.2s;pointer-events:none}
    .dropdown-panel:before,.mega-menu:before{content:"";position:absolute;left:0;right:0;top:-12px;height:12px}
    .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:translate(-50%,0);pointer-events:auto}
    .dropdown-panel a{display:block;padding:9px 10px;border-radius:8px;font-size:14px}
    .dropdown-panel a:hover{background:#eef4ff;color:var(--theme)}
    .mega-menu{width:650px;padding:22px}
    .mega-title{margin:0 0 12px;color:var(--theme);font-size:13px;font-weight:800;letter-spacing:.08em}
    .mega-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:10px}
    .mega-card{display:flex;align-items:center;gap:10px;min-width:0;padding:10px;border:1px solid #e8eef7;border-radius:11px;background:#fbfdff;transition:.2s}
    .mega-card:hover{border-color:#9cb9e7;background:#f1f6ff;transform:translateY(-2px)}
    .mega-card img{width:34px;height:34px;object-fit:contain;border-radius:7px}
    .mega-card b,.mega-card span{display:block;overflow:hidden;text-overflow:ellipsis}
    .mega-card b{font-size:13px;white-space:nowrap}
    .mega-card span span{color:var(--muted);font-size:11px;white-space:nowrap}
    .mega-links{display:grid;grid-template-columns:repeat(4,1fr);gap:8px}
    .mega-links a{padding:7px 8px;border-radius:7px;background:#f3f6fb;color:#475569;font-size:12px;text-align:center}
    .mega-links a:hover{background:#e5efff;color:var(--theme)}
    .mega-footer{display:block;margin-top:17px;padding-top:14px;border-top:1px solid #e7edf5;color:var(--theme);font-size:13px;font-weight:700}
    .header-btns{display:flex;align-items:center;gap:12px;white-space:nowrap}
    .header-btns>a:first-child{font-size:14px;color:#475569}
    .account-btn{padding:10px 17px;border-radius:9px;background:var(--theme);color:#fff;font-size:14px;font-weight:700}
    .account-btn:hover{background:var(--theme-deep)}
    .hamburger{display:none;width:42px;height:42px;border:1px solid var(--line);background:#fff;border-radius:9px;cursor:pointer;padding:9px}
    .hamburger span{display:block;height:2px;margin:5px 0;background:var(--theme);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(5,20,48,.48);opacity:0;visibility:hidden;transition:.25s;z-index:50}
    .drawer-overlay.open{opacity:1;visibility:visible}
    .mobile-drawer{position:fixed;top:0;right:0;width:min(390px,88vw);height:100vh;overflow:auto;background:#fff;transform:translateX(105%);transition:.3s;z-index:60;box-shadow:-18px 0 50px rgba(0,0,0,.16)}
    .mobile-drawer.open{transform:translateX(0)}
    .drawer-head{display:flex;align-items:center;gap:15px;padding:20px;border-bottom:1px solid var(--line);color:var(--theme);font-weight:800}
    .drawer-head a{margin-left:auto;padding:7px 13px;border-radius:7px;background:var(--theme);color:#fff;font-size:13px}
    .drawer-close{width:32px;height:32px;border:0;background:#eef3fa;border-radius:50%;font-size:24px;line-height:1;cursor:pointer;color:#475569}
    .drawer-menu{padding:13px 20px 30px}
    .drawer-link,.drawer-toggle{display:block;width:100%;padding:14px 0;border:0;border-bottom:1px solid #edf1f6;background:transparent;text-align:left;color:#1e293b;font-size:15px;cursor:pointer}
    .drawer-toggle:after{content:"+";float:right;color:var(--theme);font-size:20px}
    .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:14px}

    .tool-detail-page{padding:56px 0 80px}
    .breadcrumb{display:flex;align-items:center;gap:9px;margin-bottom:22px;color:#7a8ba5;font-size:13px}
    .breadcrumb a:hover{color:var(--theme)}
    .tool-layout{display:grid;grid-template-columns:minmax(0,1fr) 330px;gap:28px;align-items:start}
    .tool-main-card,.tool-side-card{background:var(--card);border:1px solid #e3eaf4;border-radius:var(--radius);box-shadow:var(--shadow)}
    .tool-main-card{padding:38px}
    .tool-heading{display:flex;align-items:flex-start;gap:20px;padding-bottom:27px;border-bottom:1px solid var(--line)}
    .tool-heading img{width:76px;height:76px;padding:12px;object-fit:contain;border-radius:18px;background:#edf4ff;border:1px solid #d6e5fb}
    .tool-heading h1{margin:0 0 8px;color:#0d2e65;font-size:32px;line-height:1.25}
    .tool-heading p{margin:0;color:var(--muted);font-size:16px}
    .tool-meta{display:flex;flex-wrap:wrap;gap:10px;margin-top:18px}
    .tool-meta span{padding:6px 11px;border-radius:999px;background:#eef5ff;color:var(--theme);font-size:12px}
    .tool-content{min-width:0;max-width:100%;overflow-x:auto;padding-top:28px;color:#334155;font-size:16px}
    .tool-content h2,.tool-content h3{color:#0d2e65;line-height:1.35;margin:28px 0 12px}
    .tool-content h2{font-size:23px}
    .tool-content h3{font-size:19px}
    .tool-content p{margin:0 0 16px}
    .tool-content ul,.tool-content ol{padding-left:24px}
    .tool-content table{width:100%;min-width:560px;border-collapse:collapse;margin:20px 0}
    .tool-content th,.tool-content td{padding:11px 13px;border:1px solid var(--line);text-align:left}
    .tool-content th{background:#eff5ff;color:var(--theme)}
    .tool-content img{max-width:100%;height:auto}
    .tool-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:30px;padding-top:24px;border-top:1px solid var(--line)}
    .primary-action,.secondary-action{display:inline-flex;align-items:center;justify-content:center;padding:11px 19px;border-radius:9px;font-weight:700;font-size:14px}
    .primary-action{background:var(--theme);color:#fff}
    .secondary-action{border:1px solid #bfd0e8;color:var(--theme);background:#fff}
    .tool-side-card{padding:24px;position:sticky;top:20px}
    .tool-side-card h2{margin:0 0 17px;color:#0d2e65;font-size:20px}
    .side-tool{display:grid;grid-template-columns:44px 1fr;gap:11px;padding:14px 0;border-top:1px solid #e8eef6}
    .side-tool img{width:44px;height:44px;padding:7px;object-fit:contain;border-radius:10px;background:#f0f5fb}
    .side-tool b{display:block;color:#243b63;font-size:14px;margin-bottom:3px}
    .side-tool p{margin:0;color:var(--muted);font-size:12px;line-height:1.5}
    .tool-note{margin-top:22px;padding:15px;border-radius:11px;background:#f0fbf7;border:1px solid #c8f1e2;color:#24715c;font-size:13px}

    .footer{background:#071d43;color:#b8c8df;padding:52px 0 22px}
    .footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr 1.1fr;gap:34px}
    .footer h3{margin:0 0 12px;color:#fff;font-size:20px}
    .footer h4{margin:0 0 13px;color:#fff;font-size:14px}
    .footer p{margin:6px 0;font-size:13px}
    .footer-grid>div:not(.footer-brand) a{display:block;margin:7px 0;font-size:13px;color:#b8c8df}
    .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,.14);font-size:12px;color:#8fa5c5}

    @media(max-width:1050px){
      .header-inner{gap:15px}
      .nav-link{padding:0 8px}
      .mega-menu{width:580px}
    }
    @media(max-width:820px){
      .topbar{height:auto;padding:8px 0}
      .topbar .container{align-items:flex-start;flex-direction:column;gap:2px}
      .topbar a{margin-left:15px}
      .main-nav{display:none}
      .header-inner{min-height:68px}
      .header-btns{margin-left:auto}
      .hamburger{display:block}
      .tool-layout{grid-template-columns:1fr}
      .tool-side-card{position:static}
      .footer-grid{grid-template-columns:repeat(2,1fr)}
    }
    @media(max-width:560px){
      .container{width:min(100% - 28px,1180px)}
      .header-btns>a:first-child{display:none}
      .account-btn{padding:9px 11px;font-size:12px}
      .tool-detail-page{padding:32px 0 55px}
      .tool-main-card{padding:23px 18px}
      .tool-heading{gap:13px}
      .tool-heading img{width:58px;height:58px;padding:9px;border-radius:13px}
      .tool-heading h1{font-size:24px}
      .tool-heading p{font-size:14px}
      .tool-content{font-size:15px}
      .footer-grid{grid-template-columns:1fr;gap:25px}
      .footer-bottom{display:block}
      .footer-bottom span{display:block;margin-top:7px}
    }