swiper相关系列的问题

Question

q1:想问一下swiper滑动如何固定死屏幕不让屏幕左右移动看到后面的swiper

q2:怎么才能给让导航栏整个覆盖此案例中我nav充当版心header充当整个头部当我给header添加z-index=999时整个被头部被swiper覆盖而给nav添加只有版心部分可以覆盖swiper
这是给nav添加

这是给header添加

<header>
        <div class="nav">
            <a href=""><img src="/images/huawei_logo.png" alt=""></a>
            <div class="nav_center">
                <a href="">个人及家庭产品</a>
                <a href="">商用产品及方案</a>
                <a href="">服务支持</a>
                <a href="">合作伙伴与开发者</a>
                <a href="">关于华为</a>
            </div>
            <div class="nav_last">
                    <a href="" class="buy">在线购买</a>
                    
                    <a href=""><div class="search"></div></a>
            </div>
        </div>
    </header>
    
    <div class="map_switch">
        <div class="swiper mySwiper">
            <div class="swiper-wrapper">
              <div class="swiper-slide"><img src="/images/map1.jpeg" alt=""></div>
              <div class="swiper-slide"><img src="/images/map2.jpeg" alt=""></div>
              <div class="swiper-slide"><img src="/images/map3.jpeg" alt=""></div>
            </div>
            <div class="swiper-button-next"></div>
            <div class="swiper-button-prev"></div>
          </div>
      
    </div>

header {
    
    background-color: white;
    height: 66px;
    border-bottom: 1px solid #ececec;
}
.nav {
    z-index: 999;
    position: fixed;
    left: 50%;
    transform: translateX(-50%);
    width: 1387px;
    height: 66px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    line-height: 66px;
    background-color: white;
}
.nav img {
    vertical-align: middle;
    width: 133px;
    height: 30px;
}
.nav_last {
    padding-right: 20px;
}
.nav_last::before {
    vertical-align: middle;
    content: '';
    font-family: 'icomoon';
}
.nav_last .search {
    margin-left: 40px;
    display: inline;
}
.nav_last .buy::after {
    content: '';
    font-family: 'icomoon';
    font-size: 12px;
}
.nav_last .search::after {
    content: '';
    font-family: 'icomoon';
    font-size: 20px;
}
.nav_last:hover .buy::after {
    content: '';
    font-family: 'icomoon';
}
.nav_center a {
    display: inline-block;
    height: 100%;
    padding: 0 10px;
}
.nav_center a:hover {
    border-bottom: 1px solid #b6261e;
}
.map_switch {
    position: relative;
    height: 509px;
}

Answer 1

z-index失效见文章https://www.jianshu.com/p/fb0a13c6e957