My solution. Is there anyone else?
Installed: afrux/forum-widgets-core
Installed: https://discuss.flarum.org/d/28516-custom-html-widget
Insert the following html into the "Custom Html Widget"
<!DOCTYPE html>
<html>
<head>
<style>
.navi ul {
list-style-type: none;
margin: 0;
padding: 0;
overflow: hidden;
background-color: #000;
}
.navi li {
float: left;
}
.navi li a {
display: block;
color: white;
text-align: center;
padding: 14px 16px;
text-decoration: none;
}
.navi li a:hover:not(.active) {
background-color: #111;
}
.navi .active {
background-color: #04AA6D;}
</style>
</head>
<body>
<div class="navi">
<ul>
<li><a href="link">Home</a></li>
<li><a href="link>News</a></li>
<li><a href="link">Contact</a></li>
<li style="float:right"><a class="active" href="link">About</a></li>
</ul>
</div>
</body>
</html>
It now looks like this:
