Earlier editions, kept for the record.
Applying a reset or normalize strips default styling and, in doing so, exposes the invalid markup you've been hiding.
A field guide to the mistakes that silently break stylesheets, from unitless lengths to specificity wars nobody meant to start.
A practical checklist of the markup mistakes that quietly break pages every single day.
For a few bright years we believed strictness would save us; here is what that belief got right.