CSS has been a boon to all web developers and allows for the clear separation of presentation from HTML markup. But CSS comes with it own limitations. For e.g.
- CSS does not have the ability to declare variables. Hence if you want a color to be used across multiple element types, you have to repeat the color.
- CSS does not support nesting of properties. Hence we end up repeating the code again and again.
To counter these limitations, there are new languages that have propped up that are known as 'CSS-Extension' languages. These languages support variables, nesting, etc. and make it super-easy to define themes in CSS.
Two of the most popular extension CSS languages are Less and Saas. These languages can be compiled into pure CSS language before being deployed to production.