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.
12 CSS features you can use today with no build step
Modern CSS features that replace Sass, PostCSS plugins and JavaScript hacks: nesting, :has(), container queries, subgrid and more, checked in September 2026.
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Side-by-side comparisons of outdated CSS techniques and their modern native replacements.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Side-by-side comparisons of outdated CSS techniques and their modern native replacements.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.
Prepack · Partial evaluator for JavaScript
Prepack is a tool that optimizes JavaScript source code: Computations that can be done at compile-time instead of run-time get eliminated. Prepack replaces the global code of a JavaScript bundle with equivalent code that is a simple sequence of assignments. This gets rid of most intermediate computations and object allocations.
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.
Glen Maddern: Internet Pro
Let me tell you about what CSS Modules is, and why it’s the future.
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.
