CSS nesting allows for shorter selectors, easier reading, and more modularity by nesting rules inside others.

The linear() easing function for animations and transitions interpolates linearly between the control points, and can be used to approximate complex easing functions, such as a bounce effect.

The pow(), sqrt(), hypot(), log(), and exp() CSS functions compute various exponential functions.

The hyphens CSS property controls when long words are broken by line wrapping. Although called hyphens, the property applies to word-splitting behavior across languages, such as customary spelling changes or the use of other characters. Support for non-English languages varies significantly.

The image-set() CSS function provides a set of images at different resolutions or pixel densities, which the browser can pick from, depending on the device capabilities.

The display CSS property accepts multiple keyword values, such as inline flex or block flow, to explicitly set an element's inner and outer layout mode. Also known as 2-value, multi-keyword, or multiple value syntax.

The e, pi, infinity, and NaN keywords represent well-defined constants accepted in CSS math functions such as calc().

The color-mix() function mixes two colors in a given color space and by a given amount. Commonly, lighter or darker variations of a color are created by mixing with white or black.

The sin(), cos(), tan(), asin(), acos(), atan(), and atan2() CSS functions compute various trigonometric functions.

The forced-colors CSS @media rule detects when a user has chosen to use a forced colors mode, also known as high-contrast mode, and the forced-color-adjust CSS property sets whether forced colors apply to an element.

The offset CSS property animates an element along a defined motion path.

The overflow: clip CSS declaration clips an element's overflowing content to the box that's defined by the overflow-clip-margin property. Unlike overflow: hidden, it allows you to hide overflow on one axis while keeping overflow on the other axis visible.

The @layer CSS at-rule avoids specificity conflicts by providing priority levels for different groups of CSS rules, such as low-priority styles like resets, and high-priority styles like UI components.

The appearance CSS property controls the appearance of form controls. Using appearance: none disables any default native appearance and allows the elements to be styled with CSS.

The color-scheme CSS property sets which color schemes (light or dark) an element uses and may prevent automatic dark mode adjustments by the browser.

CSS logical properties control borders, size, margin, and padding with directions and dimensions relative to the writing mode. For example, in a left to right, top to bottom writing mode, block-end refers to the bottom. Also known as flow relative.

The aspect-ratio CSS property controls the width-to-height ratio of elements. For <img> and <video> elements, the width and height attributes used together with height: auto control the aspect ratio while the image/video is loading.

The quotes CSS property sets the quotation marks inserted via the content CSS property or <q> element.

The min() and max() CSS functions return the minimum or maximum of the arguments, while clamp() clamps a value to a given range.

The overflow CSS property sets the behavior for when content doesn't fit in an element.

The CSS.supports() static method returns whether the browser supports a CSS declaration (given by two arguments, a property and value) or an @supports at-rule condition string.

The unicode-bidi and direction CSS properties override the Unicode layout algorithm. They are intended for Document Type Definition (DTD) designers. For HTML documents, you should use the dir global HTML attribute and <bdo> HTML element instead.

The caret-color CSS property sets the color of the text insertion pointer in a text input.

The display: flow-root CSS declaration sets an element as the root element of a new flow layout for its children, preventing margin collapse with sibling elements.

The will-change CSS property gives hints to the browser about expected changes to an element's scroll position, contents, or style. These hints allow browsers to optimize for upcoming style changes.

Custom properties are CSS properties prefixed with -- that set values you can reuse with the var() function. For example, you can set a --key-color property to reuse as border-color: var(--key-color). Also known as CSS variables.

The -webkit-text-stroke-width and -webkit-text-stroke-color CSS properties set the thickness and color of text outlines. The -webkit-text-fill-color sets the color within text character outlines. Both default to the text color.

The writing-mode CSS property sets whether text is laid out horizontally or vertically, and left to right, or right to left.

The filter CSS property applies one or more graphic effects to an element. You can use filter functions, such as blur() and drop-shadow(), alone or combined to produce different effects. For instance, filter: blur(2px).

The @supports at-rule applies styles based on a browser's support for CSS features, such as a CSS property and value. Also known as feature queries.