W3C home > Mailing lists > Public > www-style@w3.org > March 1999

Re: a simple question

From: Ian Hickson <py8ieh@bath.ac.uk>
Date: Tue, 9 Mar 1999 18:03:10 +0000 (BST)
To: "L. David Baron" <dbaron@fas.harvard.edu>
cc: www-style@w3.org
Message-ID: <Pine.GSO.4.04.9903091744590.23549-100000@midge.bath.ac.uk>
On Tue, 9 Mar 1999, L. David Baron wrote:

> Let me try and expand this notion a bit, and see what you all think
> of the specifics.

It all seems perfect, except for one thing.

You say:
> If user stylesheets specify any color/background pair with important
> weight for an element, then they should specify the same color for
> all descendants (using the universal selector and possibly other
> selectors) of the element and transparent (not inherit) for all
> descendants of the element. Transparent should be used so that
> positioning does not lead to covering of text. For example:
> 
> P {
>   color: black ! important;
>   background: white none ! important;
>   }
> 
> P * {
>   color: black ! important;
>   background: transparent none ! important;
>   }
> 
> P A:link { color: blue ! important; }
> P A:visited { color: purple ! important; }
> P A:active { color: red ! important; }

What if one of the P children is positioned out-of-flow so that it is
over a different element than its normal parent? 

The transparency could then clash with the new background-color,
causing a nice clash and illegible text.

eg,

HTML document:

 <P class=a>
   <EM>text</EM>
 </P>

 <DIV class=b>
   more text
 </DIV>

author css:

  * { margin: 0; padding: 0; border: none;
      font-size: inherit; line-height: inherit; }
 .a { background: maroon; color: white; }
 .b { background: green; color: white; }
 EM { position: relative; bottom: -1em; }

user.css:

  P {
    color: green ! important;
    background: white none ! important;
    }
  
  P * {
    color: inherit ! important;
    background: transparent none ! important;
    }
  
Effect:

The contents of the EM will overlap the DIV, and will be green on
green. Oops.

So - how can we guard against this?

-- 
Ian Hickson 
U+2642 U+2651
U+262E U+2603 U+263A
Received on Tuesday, 9 March 1999 13:03:30 GMT

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