.wraper {
    width: 1000px;
    margin: 0 auto
}

.nav {
    position: relative;
    width: 100%;
    height: 40px;
    background: #e9e9e9;
    overflow: hidden
}

.nav-item {
    position: relative;
    float: left;
    width: 120px;
    height: 40px;
    line-height: 40px;
    text-align: center;
    font-size: 14px;
    z-index: 1
}

.nav-item a {
    padding-top: 5px;
    font-size: 14px;
    display: block;
    height: 40px;
    color: rgb(17, 16, 16);
}

.nav-item a:hover {
    color: #fff
}

.move-bg {
    display: none;
    position: absolute;
    left: 0;
    top: 0;
    width: 120px;
    height: 40px;
    background: #333333;
    z-index: 0
}