Custom CSS

Custom CSS

Custom CSS extends Bootstrap when the built-in utilities and components do not fully match a project\'s design or behavior.

Core concept

Explain cascade order, specificity, custom classes, component modifiers, and the importance of keeping project styles separate from generated Bootstrap files.

Using it in a real interface

Create a .brand-card modifier that adds a project-specific visual treatment while retaining Bootstrap\'s card structure. Explain why a dedicated class is easier to maintain than a selector targeting several framework classes.

Implementation notes

Avoid selectors such as deeply nested .container .row .col .card rules. Small, intentional custom classes are easier to upgrade when Bootstrap changes.