I’ve been trying for an hour to remove the underline from links; I don’t understand why something that should be so simple is so difficult [closed]

Something like this should work; but without being able to see your markup, it’s hard to know for sure.

a, a:hover, a:focus, a:active {
    text-decoration: none;
}

And while I typically try to stay away from !important, sometimes it comes in handy. I’ll let you be the judge for your project on whether or not to do it this way:

a, a:hover, a:focus, a:active {
    text-decoration: none !important;
}

Specificity in CSS is something you may want to read more about, though. It would also be a good idea to get familiar with Chrome’s Developer Tools (specifically Inspector), and how to use it to troubleshoot your CSS from the frontend.