<!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 Test: table-layout: fixed - cell in the first row with specified width</title> <link rel="author" title="GĂ©rard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/" /> <link rel="help" href="http://www.w3.org/TR/CSS21/tables.html#fixed-table-layout" /> <link rel="bookmark" href="http://lists.w3.org/Archives/Public/www-style/2011Oct/0502.html" title="[css21] Section 17.5.2.1 should be clarified" /> <link rel="match" href="fixed-table-layout-003f08-ref.xht" /> <meta name="assert" content="A cell in the first row with specified non-auto 'width' sets the width for its column in the absence of a column element with specified non-auto width. This test checks the 'border-collapse: collapse' model with zero horizontal cell padding and with non-zero asymetrical horizontal cell borders." /> <style type="text/css"><![CDATA[ div, table {font: 1.25em/1.2 serif;} table { border-collapse: collapse; table-layout: fixed; width: 300px; } td {padding: 0px;} td#tested-cell { background-color: blue; border-left: orange solid 32px; border-right: orange solid 88px; color: blue; width: 80px; } div#reference { background-color: black; color: black; margin-left: 64px; /* " In the fixed table layout algorithm, the width of each column is determined as follows: (...) a cell in the first row with a value other than 'auto' for the 'width' property determines the width for that column. (...) Any remaining columns equally divide the remaining horizontal table space (minus borders or cell spacing). " Section 17.5.2.1 Fixed table layout http://www.w3.org/TR/CSS21/tables.html#fixed-table-layout Middle column width calculations -------------------------------- 16px : half of border-left since such border must be split with cell in 1st column + 80px : width of cell in the middle column + 44px : half of border-right since such border must be split with cell in 3rd column ======= 140px : width of the middle column So, 300px : table set width - 140px : width of the middle column ======= 160px So, each of the 2 remaining columns must be half of such extra horizontal table space, which is 160px divided by 2 == 80px. 1st column width calculations ----------------------------- (solve) : width of cell in 1st column + 16px : border-right since such border must be split with cell in middle column ======= 80px : width of 1st column So, the width of the cell in first column must be exactly 64px. 3rd column width calculations ----------------------------- 44px : border-left since such border must be split with cell in middle column + (solve) : width of cell in 3rd column ======== 80px : width of 3rd column So, the width of the cell in 3rd column must be exactly 36px. Finally, the precise horizontal point where the border-right of cell in first column begins to be drawn, painted is: 64px : width of cell in 1st column Therefore the margin-left: 64px value of the div#reference. */ width: 200px; } ]]></style> </head> <body> <p>Test passes if the 2 orange slivers and blue stripe are as a whole <strong>exactly as wide as</strong> the black stripe.</p> <table> <col /> <col /> <col /> <tr> <td></td> <td id="tested-cell">F08</td> <td></td> </tr> </table> <div id="reference">200px wide</div> </body> </html>