1. CSS background-position edge offsets

    Allows CSS background images to be positioned relative to the specified edge using the 3 to 4 value syntax. For example: `background-position: right 5px bottom 5px;` for positioning 5px from the bottom-right corner.

  2. 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`)`

  3. 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.

  4. audiolistener api: upx

  5. css api: dppx

  6. css api: px

  7. dommatrixreadonly api: `flipx()`

  8. types: <resolution>: `dppx` unit