Use each explanation to trace the winning CSS behavior, then inspect the related lesson before changing an application rule.
Review the lessons
- CSS cascade layers: set precedence before selectors grow
- CSS custom properties: share tokens without losing fallbacks
- CSS combinators: select relationships without encoding every wrapper
- CSS focus-visible: keep keyboard location unmistakable
Other checks
Common Mistakes
- Do not assume an answer holds when the containing markup changes.
- Do not skip keyboard and zoom review after a quiz passes.