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DEV 5.6 Use relative font sizing, not absolute units

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NDA checkpoints: 2.27, 2.5, 2.6 (P2)

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:
- px, pt, cm, ....
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, some advanced 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 %

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DEV 5.6 Use relative font sizing, not absolute units

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