CSS Reference

Use the CSS reference guides to quickly find information about CSS properties, selectors, pseudo-classes, pseudo-elements, @rules, functions, data types, values, units, color models, and other important CSS topics.

Using the CSS Reference

The CSS Reference is designed to complement the CSS Tutorials. The tutorials explain CSS concepts and techniques step by step, while the reference pages provide quick access to specific CSS information when you need to look something up.

You do not need to memorize every CSS property, selector, pseudo-class, pseudo-element, @rule, function, value, or unit. Use these reference guides while learning CSS, styling webpages, maintaining existing websites, or checking CSS code you are unfamiliar with.

CSS Properties & Selectors

CSS properties control the presentation and layout of webpage content, while selectors determine which HTML elements receive those styles. Pseudo-classes and pseudo-elements provide additional ways to select elements based on their state, position, or specific parts of their content.

CSS Property List Browse CSS properties with descriptions and links to detailed property reference pages. CSS Selector List Browse CSS selectors used to target HTML elements based on names, classes, IDs, attributes, relationships, and other criteria. CSS Pseudo-class List Browse CSS pseudo-classes used to select elements based on states, positions, user interactions, and other conditions. CSS Pseudo-element List Browse CSS pseudo-elements used to style specific parts of an element or create generated content.

CSS Rules & Functions

CSS @rules provide instructions that control stylesheets, fonts, animations, conditional styles, layers, and other CSS features. CSS functions accept values or calculations and return results that can be used within CSS declarations.

CSS @rule List Browse CSS @rules used to define stylesheet behavior, conditional rules, fonts, animations, layers, and other CSS features. CSS Function List Browse CSS functions used for calculations, colors, gradients, transforms, filters, generated values, and other CSS operations.

CSS Values

CSS declarations use data types, values, units, and color models to describe sizes, positions, colors, timing, angles, and many other characteristics. These references provide quick access to the building blocks used as CSS property values.

CSS Data Types Explore CSS data types used to represent numbers, dimensions, colors, images, positions, identifiers, and other kinds of values. CSS Values & Units Review CSS values and units used for lengths, percentages, angles, time, resolution, and other measurements. CSS Color Models Review CSS color models and formats used to define colors, including named colors, hexadecimal, RGB, HSL, HWB, and other color notations.

Additional CSS References

Additional CSS references provide quick access to browser default styles and compact guides for commonly used Flexbox and Grid layout features.

Element Default CSS Values Review common default CSS values browsers apply to HTML elements before author styles are added. Flexbox Cheat Sheet Use a compact reference for common Flexbox container and item properties, values, and layout techniques. Grid Cheat Sheet Use a compact reference for common CSS Grid container and item properties, values, tracks, placement, and alignment.

Explore the CSS Reference

Start with the CSS Property List to browse the properties available in CSS. Use the reference lists when you want to explore CSS features, or use the alphabetical navigation when you already know the property, selector, pseudo-class, pseudo-element, @rule, or function you need.