Typography in CSS controls how text appears on a webpage. Proper typography improves readability, accessibility, and visual hierarchy.

Layout systems allow developers to create structured designs such as columns, grids, navigation bars, and responsive page structures.

CSS Variables, also called Custom Properties, allow you to store reusable values (colors, spacing, sizes, etc.) and use them throughout your stylesheets.

The CSS Color system controls how colors are applied to elements, text, backgrounds, borders, and visual effects.

The CSS Box Model describes how every HTML element is structured and how its size and spacing are calculated in a webpage layout.

CSS selectors are used to target HTML elements so styles can be applied to them.