[css3-values] [css3-images] no units for default 'image-resolution'

The 'px' is defined to respect relative ocular psychophysics:

http://www.w3.org/TR/CSS21/syndata.html#numbers
http://www.w3.org/TR/css3-values/#relative0

The 'image-resolution' is by default 1 device pixel ('dppx'):

http://dev.w3.org/csswg/css3-images/#image-resolution
http://www.w3.org/TR/css3-images/#resolution-units

But there exists no image pixel unit, i.e. 'px' is not equivalent to an
image pixel.

This presents an irresolvable design error. For example, I want to put
"Shift+Enter" in tiny text inside the button for "Send" on my chat
application (because I want to support Enter normally in the <textarea>
for the text being sent).

The following works but the "Shift+Enter" overwhelms the "Send", since I
have no way to make a portion of the text within the 'value' attribute
smaller:

<input type='button' value='Send&#10;Shift+Enter'/>

The only way I found to accomplish this without making an image for the
entire button (which I don't want to do for accessibility and other
relativity breakage reasons), is as follows (and the background-image is a
transparent background GIF so the button doesn't lose background
capability).

<input type='button' style='background:url(Shift+Enter.gif) no-repeat 50%
80%; padding-bottom:10px' value='Send'/>

But the problem is that the above assumes that 'px' = '1dppx'.

Do you know any solution in current CSS? If not, I hope we can fix this.

Received on Tuesday, 26 October 2010 16:50:43 UTC