header nav ul li span {
    display: block;
    padding: 20px;
    color: #555;
    font-size: 18px;
    font-weight: 700;
    text-transform: uppercase;
    -webkit-transition: .3s;
    -o-transition: .3s;
    transition: .3s;
}
header nav ul li span img {
    width: 20px;
    height: auto;
}