The ::file-selector-button CSS pseudo-element selects the button of a <input type="file"> element.

The WeakRef and FinalizationRegistry objects hold references to garbage-collectable objects without creating strong references that prevent their garbage collection.

The Intl.DisplayNames API provides localized names of language, region, script, and currency codes.

The Intl.ListFormat API creates a locale-aware formatter that turns iterable objects into localized strings.

The AudioWorklet API runs module code in a separate thread, specifically for non-blocking, low latency audio processing.

The OfflineAudioContext API represents an audio processing graph that writes to an AudioBuffer instead of an output device.

The Web Audio API creates graphs of audio nodes that handle sound inputs, synthesize sounds, apply effects, create visualizations, and output to audio devices.

The OES_fbo_render_mipmap extension for WebGL 1.0 contexts attaches any level of a texture to a framebuffer object.

The gap CSS property in a flexbox layout sets the size of the space between items.

The rel="preload" attribute for the <link> HTML element requests resources, such as images or style sheets, that the page needs soon, so the browser may prioritize them for loading before rendering begins.

The :not() functional pseudo-class matches elements that do not match the selectors in its argument.

The clip-path CSS property and SVG attribute set the visible area of an element. Everything outside the area will be hidden.

The :where() CSS functional pseudo-class takes a selector list as its argument, and matches any element that can be selected by one of the selectors in that list. It is functionally equivalent to the selectors in the list, but doesn't affect the CSS rule specificity.

The :is() CSS functional pseudo-class takes a selector list as its argument, and matches any element that can be selected by one of the selectors in that list.