1 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
2 <html>
3 <head>
4 <title>CSS Test: Margin collapsing - parent edge and element edge are the same when margins collapse</title>
5 <link rel="author" title="Microsoft" href="http://www.microsoft.com/">
6 <link rel="help" href="http://www.w3.org/TR/CSS21/box.html#collapsing-margins">
7 <meta name="flags" content="">
8 <meta name="assert" content="When the top margin of a child box collapses with the top margin of its parent, then the margin-top edge of such child box is the same as the parent's and their respective content should be 'sitting' at the parent's border-bottom (in the testcase, the black line) assuming the same height value and the same padding-bottom value for the parent and its child box.">
9 <style type="text/css">
10 #div1
11 {
12 border-bottom: solid;
13 }
14 div div
15 {
16 height: 20px;
17 margin-top: 60px;
18 width: 60px;
19 }
20 #div2
21 {
22 background: red;
23 }
24 #div3
25 {
26 background: blue;
27 }
28 </style>
29 </head>
30 <body>
31 <p>Test passes if the blue box is touching the line and there is no red visible on the page.</p>
32 <div id="div1">
33 <div id="div2">
34 <div id="div3"></div>
35 </div>
36 </div>
37 </body>
38 </html>