<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>CSS Multi-column Layout Test: nested multi-columns and constrained dimensions</title> <link rel="author" title="Opera Software ASA" href="http://www.opera.com/" /> <link rel="reviewer" title="GĂ©rard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/" /> <!-- 2013-08-10 --> <link rel="help" href="http://www.w3.org/TR/css3-multicol/#pseudo-algorithm" title="3.4 Pseudo-algorithm" /> <link rel="match" href="multicol-nested-005-ref.xht" /> <!-- The original filename of this test was multicol-inherit-005.xht This test also serves as a conversion of multicol-nested-001.xht --> <meta name="flags" content="ahem" /> <meta name="assert" content="This test checks how the height of column boxes conditions the height of nested column boxes." /> <style type="text/css"><![CDATA[ @font-face { font-family: Ahem; src: url("../../../fonts/Ahem.ttf"); } ]]></style> <style type="text/css"><![CDATA[ body > div { -moz-column-gap: 1em; font: 1.25em/1 Ahem; width: 41em; } /* N == 3; W == max(0, (available-width - ((N - 1) * -moz-column-gap)) / N); W == max(0, (41em - ((3 - 1) * 1em)) / 3); W == max(0, (41em - (2 * 1em)) / 3); W == max(0, (41em - 2em) / 3); W == max(0, 39em / 3); W == max(0, 13em); W == 13em; The height of column rule depends on number of line boxes in each outer column box which depends on number of line boxes in each inner column box. So: 13em : width of each outer column box - 2em : horizontal margin of each div inside ======= 11em : width of each inner multi-column elements N == 3; W == max(0, (available-width - ((N - 1) * -moz-column-gap)) / N); W == max(0, (11em - ((3 - 1) * 1em)) / 3); W == max(0, (11em - (2 * 1em)) / 3); W == max(0, (11em - 2em) / 3); W == max(0, 9em / 3); W == max(0, 3em); W == 3em; So, each duo of 'a', 'm' and 'x' should fill one and only 1 line box. There are 8 duos; therefore, the first 2 inner column boxes should use 3 line boxes and the 3rd inner column box should be using 2 line boxes. So, the height of the 2 blue column rules should be 60px. */ div { background-color: yellow; color: black; font-size: 1em; margin: 1em; orphans: 1; widows: 1; -moz-column-count: 3; } div > div:first-child {margin-top: 0;} ]]></style> </head> <body> <div> <div> aa aa aa aa aa aa aa aa </div> <div> mm mm mm mm mm mm mm mm </div> <div> xx xx xx xx xx xx xx xx </div> </div> </body> </html>