Tabler is free and open-source HTML Dashboard UI Kit built on Bootstrap

Free Bootstrap 5 Admin Dashboard Template

CSS is powerful, you can do a lot of things without JS.

Free Bootstrap Admin & Dashboard Template

Free Tailwind CSS v4 components for your next project, designed to enhance your web development with the latest features and styles 🚀

🎏 A curated collection of all country flags in SVG — plus the CSS for easier integration

A minimalist CSS framework.

Open-source UI component library and front-end development framework based on Tailwind CSS

vCard is a fully responsive personal portfolio website, responsive for all devices.

A vintage 1980s DOS inspired Twitter Bootstrap theme

Open source CSS framework for data visualization.

The largest Open-Source UI Library! Community-made and free to use. Made with either CSS or Tailwind.

Style your webpage like Edward Tufte’s handouts.

Preline UI is an open-source set of prebuilt UI components based on the utility-first Tailwind CSS framework.

Card-style Hugo theme designed for bloggers

Simplest possible examples of HTML, CSS and Javascript:

CSS custom properties to help accelerate adaptive and consistent design.

MVP.css — Minimalist classless CSS stylesheet for HTML elements

CSS Reference: a free visual guide to the most popular CSS properties

Simple.css is a CSS template that allows you to make a good looking website really quickly.