4 #a { position: relative; height:
100px; width:
150px; border:
2px solid black; }
5 #b { position: absolute; left:
25px; height: auto; right:
25px; }
9 <p>The blue box should be horizontally centered in the black box with
25px of white on the left and right.
</p>
11 <img id=
"b" src=
"resources/square-blue-100x100.png">