css: Make a very thin white line in CSS

mardi 5 mai 2015

This may sound quite silly, but I have no idea how to make a thin line smaller then 1px.

What I am looking for is something like this:

If you do:

    .nav-bar {
       border-bottom: 1px;
    }

It's almost twice, if not three times as thick. As you are also probably aware, doing 1em would just round up to 1px.

Anyone have any ideas?

css