*{
    margin:0;
    padding:0;
    box-sizing: border-box;
}

/* 导航外层 */
.top-header{
    width:100%;
    background:#ffffff;
    position:fixed;
    top:0;
    left:0;
    z-index:999;
    transition: 0.3s;
}
.top-header.hide-nav{
    transform: translateY(-100%);
}
.top-header.show-nav{
    transform: translateY(0);
}

.header-inner{
    max-width:1400px;
    margin:0 auto;
    padding:0 20px;
    height:80px;
    display:flex;
    align-items:center;
    justify-content:space-between;
}

.logo-box{
    display:flex;
    align-items:center;
    gap:12px;
}
.logo-img{
    height:50px;
}

/* PC端横向菜单 */
.nav-menu{
    display:flex;
    gap:36px;
    align-items:center;
}
.nav-menu a{
    font-size:20px;
    color:#333;
    text-decoration:none;
    /* 核心：禁止文字换行！文字永远单行 */
    white-space: nowrap;
    padding:8px 0;
    position:relative;
}
.nav-menu a.active{
    color:#2468d8;
}
.nav-menu a.active::after{
    content:"";
    width:100%;
    height:3px;
    background:#2468d8;
    position:absolute;
    left:0;
    bottom:0;
}

/* 汉堡按钮 默认隐藏 */
.hamburger-btn{
    display:none;
    width:36px;
    height:30px;
    cursor:pointer;
    position:relative;
}
.hamburger-btn span{
    display:block;
    width:100%;
    height:3px;
    background:#333;
    border-radius:3px;
    position:absolute;
    transition:0.3s;
}
.hamburger-btn span:nth-child(1){top:0;}
.hamburger-btn span:nth-child(2){top:13px;}
.hamburger-btn span:nth-child(3){bottom:0;}
.hamburger-btn.active span:nth-child(1){
    transform: rotate(45deg);
    top:13px;
}
.hamburger-btn.active span:nth-child(2){
    opacity:0;
}
.hamburger-btn.active span:nth-child(3){
    transform: rotate(-45deg);
    bottom:13px;
}

/* 移动端下拉菜单 */
.mobile-nav{
    display:none;
    width:100%;
    background:#fff;
    border-top:1px solid #eee;
}
.mobile-nav.show{
    display:block;
}
.mobile-nav a{
    display:block;
    width:100%;
    text-align:center;
    padding:14px;
    font-size:18px;
    color:#333;
    text-decoration:none;
    white-space:nowrap;
}
.mobile-nav a.active{
    color:#2468d8;
}

/* =========响应式断点==========
窗口宽度小于1020px，自动隐藏横向菜单，出现汉堡按钮
觉得切换时机太早/太晚，修改数字1020即可
*/
@media (max-width: 1020px) {
    .nav-menu{
        display:none !important;
    }
    .hamburger-btn{
        display:block !important;
    }
}
#page‑zoom‑wrap {
    min-height:100vh;
}
html,body {
    overflow-x:hidden;
}