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  <title>CSS Writing Modes Test: absolutely positioned non-replaced element - 'direction: rtl' and 'top', 'height' and 'bottom' are not 'auto' (overconstrained)</title>

  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/" />
  <link rel="help" href="http://www.w3.org/TR/css-writing-modes-3/#vertical-layout" title="7.1 Principles of Layout in Vertical Writing Modes" />
  <link rel="help" href="http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width" title="10.3.7 Absolutely positioned, non-replaced elements" />
  <link rel="match" href="abs-pos-non-replaced-vlr-009-ref.xht" />

  <meta name="flags" content="ahem image" />
  <meta name="assert" content="When 'direction' is 'rtl' and 'top', 'height' and 'bottom' are not 'auto' and if the values are overconstrained, then ignore 'top' and solve for 'top'." />

  <link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
  <style type="text/css"><![CDATA[
  div#containing-block
    {
      background: red url("support/bg-red-2col-2row-320x320.png");
      color: transparent;
      direction: rtl;
      font: 80px/1 Ahem;
      height: 320px;
      position: relative;
      width: 320px;
      writing-mode: vertical-lr;
    }

  div#containing-block > span
    {
      background-color: red;
      bottom: 2em;
      color: green;
      height: 1em;
      margin-bottom: 0em;
      margin-top: 0em;
      position: absolute;
      top: 2em;
    }

/*
"
Layout calculation rules (such as those in CSS2.1, Section 10.3) that apply to the horizontal dimension in horizontal writing modes instead apply to the vertical dimension in vertical writing modes.
"
7.1 Principles of Layout in Vertical Writing Modes
http://www.w3.org/TR/css-writing-modes-3/#vertical-layout

So here, *-top and *-bottom properties are input into the §10.3.7 algorithms where *-top properties refer to *-left properties in the layout rules and where *-bottom properties refer to *-right properties in the layout rules.

"
If none of the three is 'auto': If both 'margin-left' and 'margin-right' are 'auto', solve the equation under the extra constraint that the two margins get equal values, unless this would make them negative, in which case when direction of the containing block is 'ltr' ('rtl'), set 'margin-left' ('margin-right') to zero and solve for 'margin-right' ('margin-left'). If one of 'margin-left' or 'margin-right' is 'auto', solve the equation for that value. If the values are over-constrained, ignore the value for 'left' (in case the 'direction' property of the containing block is 'rtl') or 'right' (in case 'direction' is 'ltr') and solve for that value.
"

'top' + 'margin-top' + 'border-top-width' + 'padding-top' + 'height' + 'padding-bottom' + 'border-bottom-width' + 'margin-bottom' + 'bottom' = height of containing block

So:

    160px : top
  +
      0px : margin-top
  +
      0px : border-top-width
  +
      0px : padding-top
  +
     80px : height
  +
      0px : padding-bottom
  +
      0px : border-bottom-width
  +
      0px : margin-bottom
  +
    160px : bottom
    =====================
    320px : height of containing block

gives us:

  (solve) : top
  +
      0px : margin-top
  +
      0px : border-top-width
  +
      0px : padding-top
  +
     80px : height
  +
      0px : padding-bottom
  +
      0px : border-bottom-width
  +
      0px : margin-bottom
  +
    160px : bottom
    =====================
    320px : height of containing block

And so computed top value must be 80px .
*/

  ]]></style>

 </head>

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  <p><img src="support/pass-cdts-abs-pos-non-replaced.png" width="246" height="36" alt="Image download support must be enabled" /></p>

  <div id="containing-block">1 2 34<span>X</span></div>

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