:root{
  --primary:#E8475F;
  --blue:#2563eb;
  --blue-dark:#1d4ed8;
  --ink:#0f172a;
}
/* video50 — Corporate Clean Blue 企业蓝 / 经典 SaaS / 中圆角 + 柔影 */
*{box-sizing:border-box;}
body{background:#f6f8fc;color:#475569;font-family:"Inter","Segoe UI",-apple-system,"PingFang SC","Microsoft YaHei",sans-serif;-webkit-font-smoothing:antialiased;}
::selection{background:#2563eb;color:#fff;}
::-webkit-scrollbar{width:10px;}
::-webkit-scrollbar-track{background:#eef2f8;}
::-webkit-scrollbar-thumb{background:#c3cfe0;border-radius:9999px;}

.cp-card{background:#fff;border:1px solid #e6ebf3;border-radius:.9rem;box-shadow:0 1px 2px rgba(15,23,42,.04);transition:transform .22s ease,box-shadow .22s ease,border-color .22s;}
.cp-card:hover,.cp-card.video-card:hover{transform:translateY(-4px);box-shadow:0 18px 38px -16px rgba(37,99,235,.28);border-color:#c9d8f5;}
.cp-panel{background:#fff;border:1px solid #e6ebf3;border-radius:1rem;}

.t-blue{color:#2563eb;}
.grad-blue{background:linear-gradient(135deg,#3b82f6,#2563eb);}
.t-grad{background:linear-gradient(120deg,#3b82f6,#1d4ed8);-webkit-background-clip:text;background-clip:text;color:transparent;}
.tint{background:#eef4ff;}

.cp-btn{display:inline-flex;align-items:center;gap:.45rem;font-weight:600;border-radius:.6rem;padding:.78rem 1.6rem;background:#2563eb;color:#fff;box-shadow:0 8px 20px -8px rgba(37,99,235,.65);transition:background .2s,transform .2s;}
.cp-btn:hover{background:#1d4ed8;transform:translateY(-1px);}
.cp-btn-2{display:inline-flex;align-items:center;gap:.45rem;font-weight:600;border-radius:.6rem;padding:.78rem 1.6rem;background:#fff;color:#1e293b;border:1px solid #d6deea;transition:.2s;}
.cp-btn-2:hover{border-color:#2563eb;color:#2563eb;}

.chip{border-radius:9999px;background:#eef4ff;color:#2563eb;}

.cat-tab{border-radius:.55rem;background:#fff;border:1px solid #e6ebf3;color:#64748b;font-weight:600;transition:.2s;}
.cat-tab:hover{color:#2563eb;border-color:#c9d8f5;}
.cat-tab.active{background:#2563eb;color:#fff;border-color:#2563eb;}

.nav-link{border-radius:.55rem;color:#475569;font-weight:600;transition:.2s;}
.nav-link:hover{color:#2563eb;background:#eef4ff;}
.nav-link.active{color:#2563eb;background:#eef4ff;}

.nav{display:flex;}
@media(max-width:1023px){
  .nav{position:fixed;top:0;right:0;bottom:0;width:80%;max-width:320px;flex-direction:column;align-items:stretch;gap:.4rem;background:#fff;padding:5.5rem 1.5rem 2rem;transform:translateX(102%);transition:transform .3s ease;z-index:60;overflow-y:auto;box-shadow:-16px 0 44px -14px rgba(15,23,42,.25);}
  .nav.active{transform:translateX(0);}
  .menu-overlay{position:fixed;inset:0;background:rgba(15,23,42,.4);opacity:0;visibility:hidden;transition:opacity .3s;z-index:55;}
  .menu-overlay.active{opacity:1;visibility:visible;}
  body.menu-open{overflow:hidden;}
}

.faq-answer{max-height:0;overflow:hidden;opacity:0;transition:max-height .3s ease,opacity .3s ease;}
.faq-item.active .faq-icon{transform:rotate(180deg);}
.faq-icon{transition:transform .25s ease;}

.back-to-top{opacity:0;visibility:hidden;transition:opacity .3s;}
.back-to-top.visible{opacity:1;visibility:visible;}

@media print{header,footer,.no-print{display:none;}}