Bootstrap

Bootstrap 5 dropped jQuery and embraced modern CSS (Grid, Flexbox, Variables). It remains the safest choice for admin panels and internal tools.

When to Use

• Prototypes: "Get it working" in 5 minutes.
• Admin Panels: Hundreds of templates available.
• Quick MVP: When custom design is a secondary concern.

Core Concepts

Grid System

The 12-column grid (col-md-6) is still the industry standard mental model.

Utilities

d-flex, mt-5, text-center. (Influenced Tailwind).