How Are the Parent Padding Spaces Collapsed with the Child Margins

Q

How Are the Parent Padding Spaces Collapsed with the Child Margins? - CSS Tutorials - Understanding Multiple Element Formatting Rules

✍: FYIcenter.com

A

If child block element is enclosed in a parent block element, the vertical margins of the child element could be collapsed with the padding spaces of the parent element. But this rule is Web browser dependent:

Internet Explorer (IE) collapses the parent top padding with child top margin.
Internet Explorer (IE) does not collapse the parent right, bottom and left padding with child right, bottom and left margin.
FireFox does not collapse parent padding spaces with child margins.

The tutorial HTML and CSS document below shows a good example:

<html><head>
<style type="text/css">
  H1 {font-size: 18px}
  DIV.page {width: 425px; border: 1px solid black}
  TABLE#out {background-color: #ffdddd}
  TD#box {border: 1px solid black}
  DIV#parent {width: 250px; background-color: #ffffdd;
    margin: 15px 0px 15px 0px;
    border-width: 15px 0px 15px 0px;
    padding: 15px 0px 15px 0px; 
    border-color: #ddffff;
    border-style: solid}
  P#child {width: 250px; background-color: #ddddff;
    margin: 30px 0px 30px 0px;
    border-width: 30px 0px 30px 0px;
    padding: 30px 0px 30px 0px;
    border-color: #ddffdd;
    border-style: solid}
  TD.legend {height: 29px; background-color: #ffffff}
  TD.legend#content {height: 80px}
  TD.legend#parent {height: 45px}
</style>
</head><body><div class="page">
<h1>Example of Parent-Child Padding-Margin Collapsed</h1> 
<table id=out cellpadding=0 cellspacing=0><tr>
<td id=box><div id=parent><p id=child><script language="JavaScript">
  for (i=0; i<10; i++) {
    for (j=0; j<10; j++) {
      document.write(j+' ');
    }
  }
</script></p></div></td>
<td valign=top><table>
<tr><td class=legend>- parent margin+border</td></tr>
<tr><td class=legend>- margin-top</td></tr>
<tr><td class=legend>- border-top-width</td></tr>
<tr><td class=legend>- padding-top</td></tr>
<tr><td class=legend id=content>- Content box</td></tr>
<tr><td class=legend>- padding-bottom-width</td></tr>
<tr><td class=legend>- boder-bottom</td></tr>
<tr><td class=legend>- margin-bottom</td></tr>
<tr><td class=legend id=parent>- parent padding+border+margin</td></tr>
</table></td>
</tr></table>
<p align="right">By FYICenter.com</p>
<div></body></html>

Save this document as ParentChildMargins.html, and view it with IE and FireFox, you will see the top padding of the parent block collapsed into the top margin of the child block with IE as shown in the following image:
Parent-Child Margin Handling in IE

The image below shows you that FireFox does not collapses parent padding spaces with child margins:
Parent-Child Margin Handling in FireFox

2007-05-11, 5326👍, 0💬

How Are Vertical Margins between Two Block Elements Collapsed
How Are Vertical Margins between Two Block Elements Collapsed? - CSS Tutorials - Understanding Multiple Element Formatting Rules The margins between two block elements will be collapsed into one margin. The taller margin stays. And the shorter margin disappears. The tutorial HTML and CSS document be... 2007-05-11, 6159👍, 0💬

How Are the Parent Padding Spaces Collapsed with the Child Margins
How Are the Parent Padding Spaces Collapsed with the Child Margins? - CSS Tutorials - Understanding Multiple Element Formatting Rules If child block element is enclosed in a parent block element, the vertical margins of the child element could be collapsed with the padding spaces of the parent eleme... 2007-05-11, 5327👍, 0💬

What Are White Spaces in HTML Documents
What Are White Spaces in HTML Documents? - CSS Tutorials - Understanding Multiple Element Formatting Rules White spaces are combinations of continuous white space characters: " " - The space character. "\t " - The tab character. "\n " - The new line character. "\r " - The carriage return character. 2007-05-11, 4873👍, 0💬

How Floating Elements Are Formatted
How Floating Elements Are Formatted? - CSS Tutorials - Understanding Multiple Element Formatting Rules A floating element is a block element or in-line element being specified with the "float" style property. If "float: left" is specified, a floating element will be formatted at the left margin of t... 2007-05-11, 4832👍, 0💬

How Two Block Elements Are Formatted as a Stack
How Two Block Elements Are Formatted as a Stack? - CSS Tutorials - Understanding Multiple Element Formatting Rules If two block elements are coded next to each other, they will be formatted as a vertical stack of two boxes. The HTML and CSS document below shows you a stack of two block elements: &am... 2007-05-11, 4792👍, 0💬

How To Test Child Full Width Extension
How To Test Child Full Width Extension? - CSS Tutorials - Understanding Multiple Element Formatting Rules One of the horizontal formatting rules says: if the width of the parent element is specified and greater than the full width of the child stack. the full width of the child stack will be extende... 2007-05-11, 4722👍, 0💬

How Nested Block Elements Are Formatted
How Nested Block Elements Are Formatted? - CSS Tutorials - Understanding Multiple Element Formatting Rules If a block element is nested in another block element, the inner block, child block, will be formatted as the content box of the outer block, parent block. The HTML and CSS document below shows... 2007-05-11, 4639👍, 0💬

How Is the Full Width of a Block Element Extended
How Is the Full Width of a Block Element Extended? - CSS Tutorials - Understanding Multiple Element Formatting Rules If the full width of a block element needs to be extended to meet the width of the parent element, brower will following there rules: The full width of a block element is the sum of l... 2007-05-11, 4473👍, 0💬

Why Is the Top Margin Not Showing
Why Is the Top Margin Not Showing? - CSS Tutorials - Understanding Multiple Element Formatting Rules If you are expecting a top margin to show up, and it is not showing up, it's probably because of the vertical margins collapsed due the following rules: Between two block elements - The bottom margin... 2007-05-11, 4440👍, 0💬

All rights in the contents of this web site are reserved by the individual author. fyicenter.com does not guarantee the truthfulness, accuracy, or reliability of any contents.