guideline: Distinguishable
Create content that’s easy to see and hear.
WCAG 2.0, 2.1, 2.2
Level AAA
1.4.7 Low or No Background Audio
For spoken audio content, any background noise or music is 20 decibels lower than the foreground speech.
WCAG 2.0, 2.1, 2.2
Level AAA
1.4.8 Visual Presentation
For blocks of text, justification should be avoided, line-height should be at least 1.5, width should not exceed 80 characters, and users should be able to set text and background colors.
WCAG 2.0, 2.1, 2.2
Level AAA
1.4.9 Images of Text (No Exception)
Text is actual text; never images of text.
