When you add "nofollow" value to the rel attribute of an HTML link, it basically instructs to a search engine to just ignore that link. Do you want to style these nofollow links of your website using CSS? All you have to do is write styles for this CSS selector:

a[rel~="nofollow"]

We can write styles for above CSS selector like this:

a[rel~="nofollow"] {
    background: #333 !important;
    color: #fff !important;
    text-decoration: none !important;
}

Note: Above code is only an example. You can create your own CSS.