Layout First
CSS Grid and Flexbox are not competitors — they are complementary tools. Grid excels at two-dimensional layouts (rows and columns simultaneously). Flexbox excels at one-dimensional distribution (a single row or column). Master both, and you can build any interface.
- Use Grid for page-level architecture and complex two-dimensional arrangements.
- Use Flexbox for component-level alignment and distributing space along a single axis.
- They nest perfectly — a grid item can be a flex container, and vice versa.
- Always test at multiple viewport sizes; layout behavior changes dramatically with available space.