.topnav {
    position: fixed;
    width: 100%;
    z-index: 1000;
    background: #fff;
    -webkit-box-shadow: 0 0 5px #E3E4E5;
    -moz-box-shadow: 0 0 5px #E3E4E5;
    box-shadow: 0 0 5px #E3E4E5;
    overflow: hidden;
}

.topnav nav {
    width: 1200px;
    height: 64px;
    margin: 0 auto;
}

.logo {
    height: 64px;
    float: left;
    cursor: pointer;
}

.topnav ul {
    float: right;
}

.topnav a {
    color: #000;
}

.topnav ul li {
    float: left;
    line-height: 64px;
    min-width: 80px;
    text-align: center;
    font-size: 15px;
    overflow: hidden;
    position: relative;
    padding: 0 10px;
}

.topnav ul li i{
    position: absolute;
    width: 60px;
    height: 1px;
    display: inline-block;
    left: 20%;
    /*visibility: hidden;*/
    transition: width ease 1s;
}