/* 顶部导航：全屏分区风格 + 悬停下拉 */
.xh{position:sticky;top:0;z-index:200;height:var(--nav-height,64px);background:#000;color:#fff;transition:background .3s}
.xh::after{content:"";position:absolute;left:0;right:0;top:0;height:0;background:rgba(0,0,0,.92);transition:height .25s ease;z-index:-1}
.xh.open::after{height:var(--xh-drop-h,320px)}
.xh-inner{height:100%;max-width:1600px;margin:0 auto;padding:0 3vw;display:flex;align-items:center;gap:2vw}
.xh-logo{flex:none;font:800 20px/1 var(--font-body);letter-spacing:.32em;color:#fff;text-decoration:none;white-space:nowrap}
.xh-logo span{color:var(--accent,#e8392a);letter-spacing:.32em}
.xh-nav{flex:1;display:flex;justify-content:center;height:100%}
.xh-menu{display:flex;list-style:none;margin:0;padding:0;height:100%;gap:clamp(8px,2.2vw,40px)}
.xh-item{position:relative;height:100%;display:flex;align-items:center}
.xh-top{display:flex;align-items:center;gap:7px;height:100%;padding:0 4px;background:none;border:0;color:#fff;font:700 14.5px var(--font-body);letter-spacing:.14em;cursor:pointer;white-space:nowrap}
.xh-chev{opacity:.85;transition:transform .2s}
.xh-item.open .xh-chev{transform:rotate(180deg)}
.xh-top::after{content:"";position:absolute;left:4px;right:4px;bottom:14px;height:2px;background:#fff;transform:scaleX(0);transition:transform .2s}
.xh-item.open .xh-top::after,.xh-top:hover::after{transform:scaleX(1)}
.xh-drop{position:absolute;top:100%;left:0;list-style:none;margin:0;padding:10px 0 28px;min-width:220px;opacity:0;visibility:hidden;transform:translateY(-6px);transition:opacity .2s,transform .2s,visibility .2s}
.xh-item.open .xh-drop{opacity:1;visibility:visible;transform:none}
.xh-drop a{display:block;padding:9px 4px;color:rgba(255,255,255,.88);font:700 15px var(--font-body);letter-spacing:.12em;text-decoration:none;white-space:nowrap;transition:color .15s,transform .15s}
.xh-drop a:hover,.xh-drop a:focus-visible{color:#fff;transform:translateX(4px)}
.xh-actions{flex:none;display:flex;align-items:center;gap:6px}
.xh-icon{width:40px;height:40px;display:inline-flex;align-items:center;justify-content:center;background:none;border:0;color:#fff;cursor:pointer;border-radius:50%;font-size:17px}
.xh-icon:hover{background:rgba(255,255,255,.1)}
.xh-burger{display:none;flex-direction:column;gap:5px}
.xh-burger span{display:block;width:22px;height:2px;background:#fff;transition:transform .25s,opacity .25s}
.xh-burger[aria-expanded="true"] span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.xh-burger[aria-expanded="true"] span:nth-child(2){opacity:0}
.xh-burger[aria-expanded="true"] span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

/* 首页：透明叠在首屏大图上，滚动后变黑 */
body.home .xh{position:fixed;left:0;right:0;background:linear-gradient(180deg,rgba(0,0,0,.65) 0%,rgba(0,0,0,0) 100%)}
body.home .xh.scrolled{background:#000}
body.home .breaking-news-bar{display:none}
body.home .sx-hero{min-height:100vh;min-height:100svh;padding-top:var(--nav-height,64px)}
body.admin-bar.home .xh{top:32px}

/* 手机 */
.xh-mobile{position:fixed;inset:var(--nav-height,64px) 0 0 0;z-index:199;background:#000;overflow-y:auto;padding:12px 24px 40px}
.xh-mobile[hidden]{display:none}
.xh-m-group{border-bottom:1px solid rgba(255,255,255,.12)}
.xh-m-group summary{list-style:none;display:flex;align-items:center;justify-content:space-between;padding:18px 0;color:#fff;font:700 17px var(--font-body);letter-spacing:.12em;cursor:pointer}
.xh-m-group summary::-webkit-details-marker{display:none}
.xh-m-group[open] .xh-chev{transform:rotate(180deg)}
.xh-m-group ul{list-style:none;margin:0 0 14px;padding:0}
.xh-m-group a{display:block;padding:10px 0 10px 4px;color:rgba(255,255,255,.75);font-size:15px;letter-spacing:.08em;text-decoration:none}
@media (max-width:1080px){
  .xh-nav{display:none}
  .xh-burger{display:inline-flex}
  .xh-inner{justify-content:space-between}
  .xh-logo{font-size:17px;letter-spacing:.26em}
}
@media (prefers-reduced-motion:reduce){.xh *,.xh::after{transition:none!important}}