1. CSS Container Queries (Size)

    Size queries in Container Queries provide a way to query the size of a container, and conditionally apply CSS to the content of that container.

  2. CSS Container Style Queries

    Style queries in Container Queries provide a way to query the current styling of a container, and conditionally apply additional CSS to the contents of that container.

  3. CSS Container Query Units

    Container Query Units specify a length relative to the dimensions of a query container. The units include: `cqw`, `cqh`, `cqi`, `cqb`, `cqmin`, and `cqmax`.

  4. CSS Feature Queries

    CSS Feature Queries allow authors to condition rules based on whether particular property declarations are supported in CSS using the @supports at rule.

  5. Media Queries: interaction media features

    Allows a media query to be set based on the presence and accuracy of the user's pointing device, and whether they have the ability to hover over elements on the page. This includes the `pointer`, `any-pointer`, `hover`, and `any-hover` media features.

  6. Media Queries: Range Syntax

    Syntax improvements to make media queries using features that have a "range" type (like width or height) less verbose. Can be used with ordinary mathematical comparison operators: `>`, `<`, `>=`, or `<=`. For example: `@media (100px <= width <= 1900px)` is the equivalent of `@media (min-width: 100px) and (max-width: 1900px)`

  7. Media Queries: resolution feature

    Allows a media query to be set based on the device pixels used per CSS unit. While the standard uses `min`/`max-resolution` for this, some browsers support the older non-standard `device-pixel-ratio` media query.

  8. CSS3 Media Queries

    Method of applying styles based on media information. Includes things like page and device dimensions

  9. High-quality kerning pairs & ligatures

    When used in HTML, the unofficial `text-rendering: optimizeLegibility` CSS property enables high-quality kerning and ligatures in certain browsers. Newer browsers have this behavior enabled by default.

  10. prefers-color-scheme media query

    Media query to detect if the user has set their system to use a light or dark color theme.

  11. prefers-reduced-motion media query

    CSS media query based on a user preference for preferring reduced motion (animation, etc).

  12. querySelector/querySelectorAll

    Method of accessing DOM elements using CSS selectors

  13. requestIdleCallback

    API allowing the execution of JavaScript to be queued to run in idle browser time, either at the end of a frame or when the user is inactive. Also covers support for `cancelIdleCallback`. The API has similarities with `requestAnimationFrame`.

  14. Web SQL Database

    Method of storing data client-side, allows SQLite database queries for access and manipulation.

  15. document api: querycommandenabled

  16. document api: querycommandindeterm

  17. document api: querycommandstate

  18. document api: querycommandsupported

  19. document api: querycommandvalue

  20. document api: queryselector

  21. document api: queryselectorall

  22. element api: queryselector

  23. element api: queryselectorall

  24. gpudevice api: queue

  25. path2d api: quadraticcurveto

  26. queuemicrotask api

  27. quotaexceedederror api

  28. quotaexceedederror api: quota

  29. window api: querylocalfonts

  30. css property: quotes

  31. css property: quotes: auto

  32. css property: quotes: none

  33. html element: q

  34. html element: q: cite