DEV 5.6 Use relative font sizing, not absolute units

Absolute units make resizing text in some browsers impossible for many users who may need it.

  • To size text use the following CSS values:
    • Font size keywords (recommended);
    • Percent (%);
    • <em> values.
  • Do not use:
    • pxptcm, ....
  • Put all style information including sizes in style sheets:
    • Do not use the deprecated <font> tag.
Tip: Test the results of modifications you make on several browsers. Scale from smallest to largest in Microsoft Internet Explorer and ensure text is visible at all scales.

Difficulties: Unfortunately, due to browser inconsistencies, using relative units (% <em> ) does not always produce the desired effect. At present, someadvanced workarounds are required. These use bugs in some browsers' CSS parsing to deliver accessible and compatible cross-browser scaling. Most techniques currently recommend using font size keywords.

Poor: inline font using pt and px to set font size. Poor: px setting font-size in style sheets. Good: use of keywords, em and %