Quick Update
∞@numericcitizen Here's another way, just to be clear. All done within Custom CSS (no need to edit theme files). Instead of using borders like my previous example, add this:
.post-preview:after { content: "****"; color: var(--link); }
There's a good chance you'll want to add some margin
and/or padding
to it to space it out properly, but that should be a good start.