img {
    position: fixed;
    width: 200px;
    z-index: -1;
}

span {
    user-select: false;
    cursor: default;
}

header > a {
    opacity: 0.8;
    background-color: red;
    border: none;
    color: white;
    padding: 32px 32px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 60px;
    font-family: sans-serif;
    cursor: pointer;
}

header > a:hover {
    background-color: black;
    color: white;
}