/* ============================================================
   飞创未来科技 · 全站统一导航 (site-nav)
   使用方式：页面放置 <nav class="sn" id="sn">…</nav> 统一结构，
   当前页链接加 class="on"。样式前缀 sn-，不与各页旧样式冲突。
   ============================================================ */
.sn{position:fixed;top:0;left:0;right:0;z-index:200;height:64px;
  background:rgba(10,22,51,.78);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);
  border-bottom:1px solid rgba(255,255,255,.08);transition:background .3s,box-shadow .3s}
.sn.sn-scrolled{background:rgba(10,22,51,.94);box-shadow:0 8px 30px rgba(6,14,35,.35)}
.sn-in{max-width:1220px;margin:0 auto;height:64px;display:flex;align-items:center;gap:20px;padding:0 22px}

/* 品牌 */
.sn-brand{display:flex;align-items:center;gap:10px;text-decoration:none;flex-shrink:0}
.sn-brand img{width:36px;height:36px;border-radius:9px;object-fit:cover}
.sn-brand-t{display:flex;flex-direction:column;line-height:1.2}
.sn-brand-t b{color:#fff;font-size:15px;letter-spacing:.5px}
.sn-brand-t span{color:rgba(255,255,255,.5);font-size:9.5px;letter-spacing:1.5px}

/* 链接区 */
.sn-links{display:flex;align-items:center;gap:2px;margin-left:auto}
.sn-links>a,.sn-dd-btn{position:relative;display:inline-flex;align-items:center;gap:4px;
  color:rgba(255,255,255,.78);text-decoration:none;font-size:13.5px;font-weight:600;
  padding:8px 12px;border-radius:9px;transition:.2s;background:none;border:0;cursor:pointer;
  font-family:inherit;white-space:nowrap}
.sn-links>a:hover,.sn-dd-btn:hover{color:#fff;background:rgba(255,255,255,.09)}
.sn-links>a.on{color:#fff}
.sn-links>a.on::after{content:"";position:absolute;left:12px;right:12px;bottom:3px;height:2.5px;
  border-radius:2px;background:linear-gradient(90deg,#4f8bff,#ff7a1a)}
.sn-dd-btn i{font-style:normal;font-size:10px;opacity:.6;transition:transform .2s}

/* 桌面端下拉 */
.sn-dd{position:relative}
.sn-dd-menu{position:absolute;top:calc(100% + 8px);left:50%;transform:translateX(-50%) translateY(6px);
  min-width:150px;background:#0e1f4b;border:1px solid rgba(255,255,255,.1);border-radius:13px;
  padding:7px;box-shadow:0 18px 44px rgba(4,10,26,.5);opacity:0;visibility:hidden;transition:.2s}
.sn-dd:hover .sn-dd-menu,.sn-dd:focus-within .sn-dd-menu{opacity:1;visibility:visible;transform:translateX(-50%) translateY(0)}
.sn-dd:hover .sn-dd-btn i{transform:rotate(180deg)}
.sn-dd-menu a{display:block;color:rgba(255,255,255,.82);text-decoration:none;font-size:13px;
  font-weight:600;padding:9px 13px;border-radius:8px;white-space:nowrap;transition:.15s}
.sn-dd-menu a:hover{background:rgba(255,255,255,.1);color:#fff}
.sn-dd-menu a.on{color:#7db2ff}

/* AI 平台高亮胶囊 */
.sn-platform{background:linear-gradient(100deg,#1e5eff,#4f8bff 45%,#ff7a1a)!important;
  color:#fff!important;font-weight:800!important;margin:0 6px;
  box-shadow:0 4px 16px rgba(30,94,255,.4);transition:.25s!important}
.sn-platform:hover{transform:translateY(-1px);box-shadow:0 7px 22px rgba(255,122,26,.45)}
.sn-platform em{font-style:normal;font-size:9px;font-weight:900;background:#fff;color:#ff7a1a;
  border-radius:5px;padding:1.5px 5px;margin-left:2px;letter-spacing:.5px}

/* 商务合作 CTA */
.sn-cta{border:1.5px solid rgba(255,179,71,.55)!important;color:#ffb347!important}
.sn-cta:hover{background:rgba(255,179,71,.12)!important}

/* 汉堡按钮（移动端） */
.sn-burger{display:none;flex-direction:column;justify-content:center;gap:5px;
  width:42px;height:42px;padding:10px;background:rgba(255,255,255,.08);
  border:1px solid rgba(255,255,255,.12);border-radius:10px;cursor:pointer;margin-left:auto}
.sn-burger span{display:block;height:2px;background:#fff;border-radius:2px;transition:.25s}
.sn-burger.x span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.sn-burger.x span:nth-child(2){opacity:0}
.sn-burger.x span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

/* 移动端抽屉 */
@media (max-width:960px){
  .sn-brand-t span{display:none}
  .sn-burger{display:flex}
  .sn-links{position:fixed;top:64px;left:0;right:0;bottom:0;z-index:199;
    flex-direction:column;align-items:stretch;gap:4px;padding:18px 20px 30px;
    background:rgba(8,17,40,.97);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);
    overflow-y:auto;transform:translateX(100%);transition:transform .28s ease}
  .sn-links.open{transform:translateX(0)}
  .sn-links>a,.sn-dd-btn{font-size:15px;padding:13px 16px;border-radius:12px;width:100%;justify-content:flex-start}
  .sn-links>a.on::after{display:none}
  .sn-links>a.on{background:rgba(79,139,255,.16)}
  .sn-dd{width:100%}
  .sn-dd-menu{position:static;transform:none;opacity:1;visibility:visible;display:none;
    background:rgba(255,255,255,.05);border:0;box-shadow:none;margin:2px 0 4px 14px;min-width:0}
  .sn-dd.open .sn-dd-menu{display:block}
  .sn-dd.open .sn-dd-btn i{transform:rotate(180deg)}
  .sn-dd-menu a{font-size:14px;padding:11px 14px}
  .sn-platform{justify-content:center!important;margin:10px 0 0;font-size:15px!important}
  .sn-cta{justify-content:center!important;margin-top:6px;text-align:center}
}

/* 页面内容避让：导航高 64px，各页 hero/主区已有 padding，此处仅兜底 */
@media (max-width:960px){
  .sn-in{padding:0 16px}
}