.nav_right{
    position: fixed;
    right: 50%;
    top: 50%;
    margin-right: -610px;
}
.nav_right .nav_item{
    width: 70px;
    background: #b6b6b6;
    height: 70px;
    text-align: center;
    margin-bottom: 10px;
    cursor: pointer;
    position: relative;
}
.nav_right .nav_item:hover{
    background: #808080;
}
.nav_item img{

    margin-top: 13px;
}
.nav_item a{
    display: none;
}
.nav_item:hover a{
    display: block;
    background: gray;
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    color: white;
    font-size: 20px;
    letter-spacing: 4px;
    padding-top: 7px;
    text-align: center;
}