You've probably seen the new styling of MetaCPAN by now. One anonymous monk is less than enthralled. It's not all bad, IMHO and will hopefully improve over time. Meanwhile here is the little snippet of userContent.css which I've put together today to restore a little sanity.

Update 6th Oct 2022 with a fix for the search results and similar one-pane pages:

@-moz-document url-prefix(https://metacpan.org/) {
    div.page-content { grid-template-columns: 200px calc(100vw - 200px
+) !important; }
    .no-sidebar div.page-content { grid-template-columns: 1fr !importa
+nt; }
    ul.nav-list { padding: 10px !important; width: 200px !important }
    ul.nav-list>li a, ul.dependencies>li>a { color: #337ab7 !important
+ }
    div.content { padding: 20px !important }
    #index-container { margin-left: 20px !important }
}
[download]

Original attempt was:

@-moz-document url-prefix(https://metacpan.org/) {
    div.page-content { grid-template-columns: 200px calc(100vw - 200px
+) !important; }
    ul.nav-list { padding: 10px !important; width: 200px !important }
    ul.nav-list>li a, ul.dependencies>li>a { color: #337ab7 !important
+ }
    div.content { padding: 20px !important }
    #index-container { margin-left: 20px !important }
}
[download]

This will:

• Reduce the left nav from 300 to 200 pixels in width and reduce the padding on the main content so there is not so much wasted space (Don't ask me why they've gone with a fixed pixel width here to begin with)
• Re-enable the different styling (colour) of links in the nav so you can tell what is a link and what is just info once again

We'll see how much this needs tweaking over the next little while but at least if you are interested in this it saves us all reverse-engineering it independently.

The new layout proposal and discussion is in the issues here.