Hello, there has been a discussion this week about the print stylesheet, when I reported a malfunction of Firefox (2.0 under Windows XP) with scaling. Looking at the Firefox bugzilla it seems that there actually is a bug in the Gecko engine regarding the (MS-Windows) print scaling feature.
Maybe it was not wise to adress this issue from the side of browser behaviour. I would like the Mediawiki developer community to reconsider the point about fixed font sizes in stylesheets - based on the position of an independent mediator in HTML/CSS coding, the W3C:
- Web content accessibility guidelines: "Use relative rather than absolute units in markup language attribute values and style sheet property values." ( http://www.w3.org/TR/WCAG10-CSS-TECHS/#units )
- Quality assurance: "Units: avoid absolute length units for screen display. .. Do not specify the font-size in pt, or other absolute length units for screen stylesheets. They render inconsistently across platforms and can't be resized by the User Agent (e.g browser). Keep the usage of such units for styling on media with fixed and known physical properties (e.g print)." ( http://www.w3.org/QA/Tips/font-size )
- An example from an organisation's guideline (State of Kansas): "Use relative rather than absolute units of measure (e.g., for margins, font sizes, borders, etc.)." ( http://www.da.ks.gov/itec/WASPriorities112001.htm classified as priority 2 - "Web developers must satisfy this item." )
Now looking at the en.wikipedia.org stylesheets we see fixed font sizes only in commonprint.css ( http://en.wikipedia.org/skins-1.5/common/commonPrint.css?42 ), in the 'content' and 'pre' styles.
Regarding the QA citation, yes this is a print media - but why should wikipedia try to produce a fixed page layout on a users printer?
At the time the stylesheet was designed I might have been the best choice to set a fixed size (liek 'content .. 11pt') to get a fairly consistent result on the browsers of that time. But with the actual versions of popular browsers we see more consistent compliance with CSS specs.
The effort to change this setting to an 'em' or '%' value is minimal, the risk for incompatability is zero. So please consider again to change this.
Greetings // Bernd