CSS now has user-defined functions. No preprocessor, no JavaScript, but native @function with typed parameters, local variables, and conditional logic built right into your CSS.
CSS selectors - CSS | MDN
The CSS selectors module defines the patterns to select elements to which a set of CSS rules are then applied along with their specificity. The CSS selectors module provides us with more than 60 selectors and five combinators. Other modules provide additional pseudo-class selectors and pseudo-elements.
Pseudo-classes - CSS | MDN
A CSS pseudo-class is a keyword added to a selector that lets you select elements based on information that lies outside of the document tree, such as a specific state of the selected element(s). For example, the pseudo-class :hover can be used to style a button when a user's pointer hovers over it.
element() CSS function - CSS | MDN
The element() CSS function defines an <image> value generated from an arbitrary HTML element. This image is live, meaning that if the HTML element is changed, the CSS properties using the resulting value are automatically updated.
2026 CSS wishlist – Nathan Knowler
What I’d like to see prioritized for CSS in 2026, how those features will allow us to create better web-based design systems, and how they renew separation of concerns.
JavaScript Guide - JavaScript | MDN
The JavaScript Guide shows you how to use JavaScript and gives an overview of the language. If you need exhaustive information about a language feature, have a look at the JavaScript reference.
Modern CSS snippets. Every old hack, replaced.
Side-by-side comparisons of outdated CSS techniques and their modern native replacements. Grid, custom properties, nesting, container queries, and more.
Modern CSS snippets. Every old hack, replaced.
Side-by-side comparisons of outdated CSS techniques and their modern native replacements. Grid, custom properties, nesting, container queries, and more.
Doing maths in CSS
sin(), cos(), atan2() landed in CSS in 2023. You can now place elements in circles, arcs, and spirals with pure CSS, no JavaScript, no libraries. Here's how the math works.
Vanilla CSS is all you need
Campfire, Writebook, and Fizzy show that modern vanilla CSS can power serious apps without Sass, PostCSS, or a build step.
7 CSS Tricks That Actually Have Good Browser Support
18 Best CSS Libraries/Frameworks for UI/UX Designs 2024
Here are the 25 best CSS libraries/frameworks for UI/UX designs which make your frontend development more easier and productive with custom features.
CSS Formatter, CSS Beautifier and CSS Minifier Online tool
Best Online CSS Formatter, CSS Beautifier, CSS Minifier, Save and Share CSS. Simple Quick and Fast!
The CSS Selection - 2026 Edition - Project Wallace
The CSS Selection shows real-world CSS usage from over 100,000 websites and looks at the most important metrics.
Bring the Console API to CSS with css-console