:root{
  --theme:#0B3D91;
  --ink:#172033;
  --muted:#667085;
  --line:#e5eaf2;
  --paper:#f6f8fc;
  --white:#fff;
  --shadow:0 18px 50px rgba(25,43,78,.10);
  --radius:18px
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;color:var(--ink);background:var(--paper);font-family:"PingFang SC","Microsoft YaHei",Arial,sans-serif;line-height:1.65}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
button{font:inherit}
.container{width:min(1180px,calc(100% - 40px));margin:auto}
.topbar{background:#101a2d;color:#cbd5e1;font-size:13px}
.topbar .container{min-height:36px;display:flex;align-items:center;justify-content:space-between;gap:16px}
.topbar a{color:#e8eefb;margin-left:18px}
.header{position:sticky;top:0;z-index:30;background:rgba(255,255,255,.96);border-bottom:1px solid var(--line);backdrop-filter:blur(16px)}
.header-inner{height:78px;display:flex;align-items:center;gap:30px}
.logo{display:flex;align-items:center;gap:10px;white-space:nowrap;font-size:19px;font-weight:800;color:var(--theme)}
.logo img{width:34px;height:34px;object-fit:contain}
.main-nav{flex:1}
.nav-list{display:flex;align-items:center;justify-content:center;gap:5px;padding:0;margin:0;list-style:none}
.nav-item{position:relative}
.nav-link{display:block;padding:27px 13px;font-size:14px;font-weight:700;color:#26334a}
.nav-link:hover,.nav-link:focus{color:var(--theme)}
.has-arrow:after{content:"";display:inline-block;width:6px;height:6px;margin:0 0 3px 7px;border-right:1px solid currentColor;border-bottom:1px solid currentColor;transform:rotate(45deg)}
.dropdown-panel,.mega-menu{position:absolute;top:calc(100% - 1px);left:50%;transform:translateX(-50%);width:350px;padding:16px;background:#fff;border:1px solid var(--line);border-radius:0 0 16px 16px;box-shadow:var(--shadow);opacity:0;visibility:hidden;pointer-events:none;transition:.2s;z-index:40}
.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;pointer-events:auto}
.dropdown-panel:before,.mega-menu:before{content:"";position:absolute;left:0;right:0;top:-12px;height:12px}
.dropdown-panel>a:not(.mega-footer){display:block;padding:10px 8px;border-bottom:1px solid #eef1f6}
.dropdown-panel strong,.mega-card strong{display:block;font-size:14px}
.dropdown-panel small,.mega-card small{display:block;color:var(--muted);font-size:12px;line-height:1.5;margin-top:4px}
.mega-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.mega-card,.mega-grid>a:not(.mega-card){display:block;padding:13px;border:1px solid var(--line);border-radius:12px;background:#fbfcff;transition:.2s}
.mega-card:hover,.mega-grid>a:not(.mega-card):hover{border-color:#9eb7df;background:#f1f6ff}
.mega-card img{width:28px;height:28px;object-fit:contain;margin-bottom:8px}
.mega-footer{display:block;margin-top:14px;padding-top:12px;border-top:1px solid var(--line);color:var(--theme);font-size:13px;font-weight:700}
.header-btns{display:flex;align-items:center;gap:9px;white-space:nowrap}
.member-btn,.account-btn{padding:9px 14px;border-radius:10px;font-size:13px;font-weight:700}
.member-btn{color:var(--theme);background:#edf3ff}
.account-btn{color:#fff;background:var(--theme)}
.hamburger{display:none;width:40px;height:38px;padding:8px;border:1px solid var(--line);border-radius:9px;background:#fff;cursor:pointer}
.hamburger span{display:block;width:21px;height:2px;margin:4px auto;background:var(--ink);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(12,25,49,.48);opacity:0;visibility:hidden;z-index:50;transition:.2s}
.drawer-overlay.open{opacity:1;visibility:visible}
.mobile-drawer{position:fixed;right:0;top:0;bottom:0;width:min(380px,88vw);padding:22px;background:#fff;z-index:51;transform:translateX(100%);transition:.25s;overflow:auto}
.mobile-drawer.open{transform:translateX(0)}
.drawer-head{display:flex;align-items:center;gap:12px;padding-bottom:18px;border-bottom:1px solid var(--line)}
.drawer-head strong{flex:1;color:var(--theme)}
.drawer-head a{padding:7px 12px;border-radius:8px;background:var(--theme);color:#fff;font-size:13px}
.drawer-close{border:0;background:transparent;font-size:28px;line-height:1;cursor:pointer;color:var(--muted)}
.drawer-menu{padding-top:10px}
.drawer-link,.drawer-toggle{display:block;width:100%;padding:14px 4px;border:0;border-bottom:1px solid #eef1f6;background:transparent;text-align:left;color:var(--ink);font-weight:700;cursor:pointer}
.drawer-toggle:after{content:"+";float:right;color:var(--theme);font-size:20px;font-weight:400}
.drawer-toggle.active:after{content:"−"}
.drawer-submenu{display:none;padding:5px 0 7px 15px}
.drawer-submenu.open{display:block}
.drawer-submenu a{display:block;padding:9px 4px;color:var(--muted);font-size:14px}
.footer{margin-top:70px;padding:50px 0 20px;background:#101a2d;color:#c5d0e3}
.footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1fr 1fr;gap:35px}
.footer-brand{font-size:21px;color:#fff;font-weight:800;margin-bottom:14px}
.footer p{margin:8px 0;color:#aebbd0;font-size:13px}
.footer h3{margin:0 0 14px;color:#fff;font-size:15px}
.footer-grid>div>a{display:block;margin:8px 0;color:#b7c4da;font-size:13px}
.footer-grid>div>a:hover{color:#fff}
.footer-bottom{margin-top:35px;padding-top:18px;border-top:1px solid rgba(255,255,255,.12);color:#91a0b8;font-size:12px;text-align:center}

.tool-detail-page{padding:54px 0 20px}
.tool-detail-page .breadcrumb{display:flex;flex-wrap:wrap;gap:8px;align-items:center;color:var(--muted);font-size:13px;margin-bottom:24px}
.tool-detail-page .breadcrumb a{color:var(--theme)}
.tool-layout{display:grid;grid-template-columns:minmax(0,1fr) 310px;gap:28px;align-items:start}
.tool-main,.tool-sidebar{background:#fff;border:1px solid var(--line);border-radius:var(--radius);box-shadow:0 10px 35px rgba(27,47,82,.05)}
.tool-main{padding:36px}
.tool-heading{display:flex;align-items:flex-start;gap:20px;padding-bottom:25px;border-bottom:1px solid var(--line)}
.tool-icon{width:76px;height:76px;flex:0 0 76px;padding:13px;border-radius:18px;background:#eef4ff;object-fit:contain}
.tool-heading h1{margin:0 0 8px;font-size:clamp(27px,4vw,42px);line-height:1.2;color:#12223e}
.tool-intro{margin:0;color:var(--muted);font-size:16px}
.tool-meta{display:flex;flex-wrap:wrap;gap:10px 22px;margin-top:17px;color:var(--muted);font-size:13px}
.tool-meta b{color:var(--ink);font-weight:600}
.tool-content{min-width:0;max-width:100%;overflow-x:auto;padding-top:28px;color:#354258}
.tool-content img,.tool-content video,.tool-content iframe{max-width:100%}
.tool-content table{max-width:100%;border-collapse:collapse}
.tool-content h2,.tool-content h3{color:#12223e;margin-top:28px}
.tool-content p{margin:0 0 18px}
.tool-actions{display:flex;flex-wrap:wrap;gap:12px;margin-top:28px;padding-top:24px;border-top:1px solid var(--line)}
.primary-btn,.ghost-btn{display:inline-flex;align-items:center;justify-content:center;padding:11px 19px;border-radius:10px;font-size:14px;font-weight:700}
.primary-btn{background:var(--theme);color:#fff}
.ghost-btn{border:1px solid #cbd7ea;color:var(--theme);background:#fff}
.tool-sidebar{padding:24px;position:sticky;top:105px}
.tool-sidebar h2{margin:0 0 16px;font-size:19px;color:#12223e}
.related-tool{display:grid;grid-template-columns:43px 1fr;gap:11px;padding:14px 0;border-top:1px solid var(--line)}
.related-tool:first-of-type{border-top:0}
.related-tool img{width:43px;height:43px;padding:7px;border-radius:10px;background:#eef4ff;object-fit:contain}
.related-tool strong{display:block;font-size:14px;line-height:1.4}
.related-tool p{margin:4px 0 0;color:var(--muted);font-size:12px;line-height:1.45}
.side-more{display:block;margin-top:14px;padding-top:14px;border-top:1px solid var(--line);color:var(--theme);font-size:13px;font-weight:700}
@media(max-width:1050px){
  .header-inner{gap:15px}
  .nav-link{padding-left:8px;padding-right:8px}
  .member-btn{display:none}
}
@media(max-width:820px){
  .topbar .container{padding:7px 0;align-items:flex-start;flex-direction:column;gap:2px}
  .topbar a{margin:0 14px 0 0}
  .main-nav{display:none}
  .hamburger{display:block}
  .header-inner{height:68px}
  .tool-layout{grid-template-columns:1fr}
  .tool-sidebar{position:static}
}
@media(max-width:600px){
  .container{width:min(100% - 28px,1180px)}
  .account-btn{display:none}
  .tool-detail-page{padding-top:30px}
  .tool-main{padding:22px 18px}
  .tool-heading{gap:13px}
  .tool-icon{width:57px;height:57px;flex-basis:57px;padding:10px;border-radius:13px}
  .tool-heading h1{font-size:27px}
  .tool-intro{font-size:14px}
  .footer{margin-top:42px;padding-top:35px}
  .footer-grid{grid-template-columns:1fr 1fr;gap:25px 18px}
  .footer-grid>div:first-child{grid-column:1/-1}
}