The font-variant-alternates CSS property, along with the @font-feature-values at-rule, chooses when to use a font's alternate glyphs.

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

The color-gamut media query sets styles based on the colors a device can display.

Container size queries with the @container (…) at-rule apply styles to an element based on a dimension of its container, such as width or height.

MathML, or the Mathematical Markup Language, describes mathematical notation, such as expressions and formulas. Also known as MathML Core.

The OES_draw_buffers_indexed extension for WebGL 2.0 contexts allows you to control blending on a per-color basis when writing to multiple color buffers simultaneously.

The sv*, lv*, and dv* CSS viewport units are relative to the smallest, largest, and current (dynamic) viewport size. They are used to size elements in relation to the viewport's dimensions.

The font-palette CSS property selects a color palette from the font, optionally overriding individual colors in the @font-palette-values at-rule.

Grid animation allows you to animate the grid-template-columns and grid-template-rows CSS properties.

The ic CSS length unit corresponds to the width of CJK ideographic characters.

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 text-align-last CSS property sets the alignment of the last line of text before a forced line break.

The resolution CSS media query sets styles based on the pixel density, or how many pixels a device uses to display a single CSS pixel.

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

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 contain: inline-size CSS declaration prevents the element's inline dimension from being set by the element's contents. This permits the browser to avoid slower layout calculations.

The navigator.permissions API checks whether a permission, such as access to geolocation data, has been granted.

The :modal pseudo-class selects elements that put other elements into a non-interactive state, such as a fullscreen element or a <dialog> element used with showModal().

The findLast() and findLastIndex() methods of arrays and typed arrays search an array in reverse order for the first item that satisfies a test function.

The translate, rotate, and scale CSS properties apply single transformations independently, as opposed to applying multiple transformations with the transform CSS property.

The contain: style CSS declaration permits the browser to avoid slower layout calculations by preventing modification to counter (counter-increment and counter-set) and quotation styles (content property quote values) beyond the element's descendants.

The streams API creates, composes, and consumes continuously generated data.

The prefers-contrast CSS media query sets styles based on whether the user prefers more or less contrast, the difference between foreground and background colors.

Exceptions break the normal control flow of execution to represent exceptional behavior, such as an error. You can respond to the exception in JavaScript code.

The dynamic-range CSS media query sets styles based on whether a device can display at least standard range colors or at least high range colors. Non-visual devices will match neither.

The navigator.mediaCapabilities API queries the encoding and decoding abilities of the device, such as supported codecs, resolutions, and bitrates.

The hwb() CSS function picks colors using hue, whiteness, and blackness channels.

The text-decoration-skip-ink CSS property sets whether underlines and overlines may be interrupted where the line would cross a glyph.

The Object.hasOwn() static method checks whether an object has a given property. It's a more robust alternative to the Object.prototype.hasOwnProperty() method.

The contain CSS property sets limits to the scope of styles, layout, and paint rendering for speed and efficiency. The none keyword value disables containment, strict is equivalent to contain: size layout style paint, and content is equivalent to contain: layout style paint.