absolute-non-replaced-height-004.xht (2031B)
1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 2 <html xmlns="http://www.w3.org/1999/xhtml"> 3 <head> 4 <title>CSS Test: Absolutely positioned, non-replaced elements, 'margin-top' set to 'auto'</title> 5 <link rel="author" title="Microsoft" href="http://www.microsoft.com/" /> 6 <link rel="reviewer" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/" /> <!-- 2012-08-31 --> 7 <link rel="help" href="http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-height" /> 8 <link rel="match" href="absolute-non-replaced-height-003-ref.xht" /> 9 10 <meta name="assert" content="When 'top', 'bottom', 'height' and 'margin-bottom' of an absolutely positioned, non-replaced element are all not 'auto' while its 'margin-top' is 'auto', then 'margin-top' becomes the remainder of the height of its containing block." /> 11 <style type="text/css"> 12 #div1 13 { 14 border: solid black; 15 height: 3in; 16 position: relative; 17 width: 3in; 18 } 19 div div 20 { 21 background: blue; 22 bottom: 0.5in; 23 height: 1in; 24 margin-top: auto; 25 margin-bottom: 0.5in; 26 position: absolute; 27 top: 0.5in; 28 width: 100%; 29 } 30 31 /* 32 33 0.5in : top 34 + 35 auto (solve): margin-top 36 + 37 0 : border-top-width 38 + 39 0 : padding-top 40 + 41 1in: height 42 + 43 0 : padding-bottom 44 + 45 0 : border-bottom-width 46 + 47 0.5in : margin-bottom 48 + 49 0.5in : bottom 50 ============= 51 3.0in : height of containing block 52 53 So, margin-top must use 0.5in so that the equation gets balanced. 54 55 */ 56 57 </style> 58 </head> 59 <body> 60 <p>Test passes if a blue rectangle is <strong>vertically centered</strong> in an hollow black square.</p> 61 <div id="div1"> 62 <div></div> 63 </div> 64 </body> 65 </html>