Add conceptual explanations to all 4 lessons in 05-units-variables.json:
- Lesson 1 (Absolute vs Relative Units): Explains fixed px vs scalable rem/%, why rem is preferred for accessibility, and how units calculate
- Lesson 2 (CSS Custom Properties): Explains variable definition/reference, inheritance cascade, scoping, and live updates vs preprocessor variables
- Lesson 3 (calc): Explains runtime calculation, mixing units, syntax requirements for operators
- Lesson 4 (Viewport Units): Explains vw/vh/vmin/vmax relative to viewport, auto-resize behavior, and difference from percentage units
All concepts include beginner-friendly explanations (2-4 sentences) and detailed ASCII diagrams showing calculations and visual representations.
Michael Czechowski
9dc06012f1