/* 顶部头部导航 */
.header-top{height:50px;background:#000;display:flex;align-items:center;padding:0 20px;gap:20px;}
.logo{color:#fff;font-size:18px;font-weight:bold;white-space:nowrap;}
.logo a{color:#fff;}
.search-wrap{flex:1;display:flex;justify-content:right;}
.search-box{width:340px;height:34px;display:flex;}
.search-box input{flex:1;height:100%;padding:0 12px;border:none;outline:none;font-size:14px;background:#fff;color:#000;}
.search-box button{width:60px;height:100%;border:1px solid #ddd;background:#fff;color:#000;cursor:pointer;font-size:14px;}
.menu-toggle{width:40px;height:34px;background:#000;border:1px solid #fff;color:#fff;cursor:pointer;font-size:18px;display:flex;align-items:center;justify-content:center;flex-shrink:0;display:none;}

/* 二级通栏主导航 */
.main-nav{background:#333;display:none;}
.main-nav.active{display:block;}
.nav-list{max-width:1200px;margin:0 auto;display:flex;}
.nav-item{position:relative;padding:0 22px;height:46px;display:flex;align-items:center;cursor:pointer;}
.nav-item>a{color:#fff;font-size:14px;}
.nav-item .arrow{font-size:12px;margin-left:4px;}
.sub-menu{position:absolute;top:46px;left:0;background:#fff;border:1px solid #ddd;min-width:140px;display:none;z-index:99;}
.sub-menu li{padding:10px 16px;}
.sub-menu li a{color:#000;font-size:14px;}
.nav-item:hover .sub-menu{display:block;}
.sub-menu li a:hover{color:#666;}

/* 响应式断点 PC≥1200 | 平板768-1199 | 手机≤767 */
@media screen and (min-width:1200px){
    .main-nav{display:block;}
}
@media screen and (min-width:768px) and (max-width:1199px){
    .header-top{flex-wrap:wrap;height:auto;padding:12px 20px;align-items:flex-start;}
    .search-wrap{order:3;width:100%;justify-content:flex-start;margin-top:10px;}
    .search-box{width:100%;max-width:420px;}
    .nav-list{flex-wrap:wrap;}
    .nav-item{width:auto;height:42px;}
}
@media screen and (max-width:767px){
    .header-top{flex-wrap:wrap;height:auto;padding:12px 15px;}
    .logo{order:1;}
    .menu-toggle{display:flex;order:2;margin-left:auto;}
    .search-wrap{order:3;width:100%;margin-top:10px;}
    .search-box{width:100%;}
    .nav-list{flex-direction:column;max-width:100%;}
    .nav-item{width:100%;height:auto;padding:0 15px;flex-direction:column;align-items:flex-start;padding-top:8px;padding-bottom:8px;}
    .sub-menu{position:static;display:block !important;border:none;background:#444;width:100%;margin-top:6px;display:flex !important;flex-wrap:wrap;gap:4px 12px;padding:4px;}
    .sub-menu li{padding:4px 0;}
    .sub-menu li a{color:#ffffff;}
    .nav-item .arrow{display:inline-block !important;}
    .nav-item:hover .sub-menu{display:flex !important;}
}