If you are a Front-end Web developer , then CSS designs are some of the Skills which will boost your UI Designing Skills exponentially.

Here are few CSS Frameworks to Start with

1. Bootstrap ( getbootstrap.com )
   • More than 146k Stars , 71.5k forks and 1169+ contributors on Github
   • Time Saver
   • Prevent any browser compatibility testing Issues
   • Well-maintained Codebase
   • Better consistency and teamwork
2. Foundation ( get.foundation )
   • More than 28.9k stars , 5.8k forks , and 1027 contributors on Github
   • The base CSS appearances are built in and there won't be much CSS bloat in the HTML
   • Foundation provides you with a HTML5 form validation library.
3. Tailwind CSS ( tailwindcss.com )
   • More than 33.5k stars , 1.5k forks and 152 contributors on Github
   • Tailwind was built from the ground-up to be super customizable
   • Built-in design system
   • Naming conventions are pretty straightforward
4. Semantic UI ( semantic-ui.com )
   • More than 48.9k stars , 5.1k forks and 201 contributors on Github
   • Semantic UI is very intuitive
   • Availability of a Plethora of themes
   • Powerful tools for expressing groups and collections
5. Materialize CSS ( materializecss.com )
   • More than 38.3k stars, 4.9k forks and 262 contributors on Github
   • Great plugins available
   • Some other great features like parallax elements , cards , flow texts , hover able items as well as objects.