4 border:2px solid black;
8 width: calc(50% - 10px);
10 background-color:purple;
12 .left { float: left; }
13 .right { float: right; }
15 The two purple rectangles below should both be at the top of their columns. If one is lower than the other, than the test has failed.
17 <div class="block left"></div>
18 <div class="block right"></div>