Frameworks

CSS Frameworks

Websites
tailwindcss
Bootstrap
Bulma
Zurb Foundation
Materialize
Bootswatch
Tailwind components
Ready-to-use Tailwind CSS blocks
tailwindUI - Tailwind UI Components
Tailwind Cheat-Sheet

CSS Tools

Websites
flexbox
CSS GRID
cssmastery
CSS Button Generator
Box Shadows
Flexplorer
CSS Grid Generator
CSS Specificity calculator
Specificity calculator
CSS clip-path Maker
Custom Shape Dividers
Fancy-Border-Radius
Houdini.how
Neumorphism.io
Glassmorphism.com
3D Book
98.css
Enjoy CSS - Online CSS Code Generator
CSS Arrow Please
Image Effects with CSS