Highlight current link with Swup.js

I use Swup for page transitions and was wondering how I could highlight the currently active link. Imagine I have a page structure like:

<nav>
  <a href="/page-1">Page 1</a>
  <a href="/page-2">Page 2</a>
</nav>
<main id="swup">
  <!-- content -->
</main>

After each nav a click, the page content is being replaced, but I want to have a different style for the currently active link.

Thanks for any help!

You can use the Swup contentReplaced hook to listen for completed page loads, loop through all links that match a specified selector and check if their hrefs are identical to the current url.

function swupActiveLinks(){
    let currentPath = window.location.pathname;
    let links = document.querySelectorAll('nav a'); // <- put your link selector here
    for (const link of links) {
        let linkPath = (new URL( link.href )).pathname;
        link.ariaCurrent = linkPath == currentPath ? 'page' : false;
    }
}
swup.on('contentReplaced', () => {
    swupActiveLinks(); // trigger after swup
});
swupActiveLinks(); // trigger on page load

Then style all current links:

nav a[aria-current=page]{
  text-decoration: underline;
}