<!DOCTYPE html>
<p>Test adding ::before and ::after pseudo elements that are spanners.</p>
<p>There should be three rectangles with identical sizes below. The first and third one
    should be yellow with some dots inside. The second one should be blue with nothing
    inside.</p>
<div style="line-height:100px; background:blue;">
    <div style="background:yellow;">..........</div>
    <br>
    <div style="background:yellow;">..........</div>
</div>