MediaWiki:Common.css

[name=pluggableauthlogin0] {
    display: inline-block;
    background: white;
    color: #444;
    width: 190px;
    border-radius: 5px;
    border: thin solid #888;
    box-shadow: 1px 1px 1px grey;
    white-space: nowrap;
}

[name=pluggableauthlogin0]:hover {
    cursor: pointer;
}