/* 零号湾 · 全站主导航（跨子系统） */
.sitenav{position:sticky;top:0;z-index:200;background:#fff;border-bottom:1px solid #E5E7EB;
  display:flex;align-items:center;gap:18px;padding:0 24px;height:54px;
  font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif}
.sitenav .sn-brand{font-weight:700;font-size:16px;color:#0D56A6;text-decoration:none;white-space:nowrap;margin-right:6px}
.sitenav .sn-links{display:flex;align-items:center;gap:2px;margin-left:auto;flex-wrap:wrap}
.sitenav .sn-links a{color:#1F2937;text-decoration:none;font-size:14px;padding:8px 12px;border-radius:8px;
  transition:background .2s,color .2s;white-space:nowrap}
.sitenav .sn-links a:hover{background:#F5F7FA;color:#0D56A6}
.sitenav .sn-links a.active{color:#0D56A6;background:#E8F1FA;font-weight:600}
.sitenav .sn-toggle{display:none}
@media(max-width:768px){
  .sitenav{flex-wrap:wrap;height:auto;padding:10px 16px;gap:10px}
  .sitenav .sn-links{width:100%;display:none;flex-direction:column;align-items:stretch;gap:2px;margin-left:0}
  .sitenav.open .sn-links{display:flex}
  .sitenav .sn-toggle{display:block;margin-left:auto;background:#fff;border:1px solid #E5E7EB;
    border-radius:8px;font-size:18px;line-height:1;padding:4px 12px;cursor:pointer}
}