/* Source: http://test.csswg.org/suites/css2.1/20110323/html4/inline-block-zorder-005.htm */

div#test > span { display:inline-block; vertical-align: top; }
div#test > span > span { display: block; background: green; color: green; border-bottom: 0.25em solid green; border-top: 0.25em solid green; }
div#before { height: 1em; margin-bottom:-1em; }
div#before > span { display: inline; vertical-align: top; background: red; color: red; }