img {
    width: 80px;
    height: 80px;
}

.header {
    padding-top: 5px;
    width: 100%;
    height: 90px;
    overflow: auto;
    padding-left: 10px;
    background: royalblue;
}

.header a {
    margin-top: 25px;
    margin-right: 20px;
    text-align: center;
    padding: 12px;
    color: white;
    text-decoration: none;
    font-size: 17px;
}

@media screen and (max-width: 500px) {
    .header a {
        float: none;
        display: block;
    }
}