Can I use
?

background-position-x & background-position-y

- UNOFF

CSS longhand properties to define x or y positions separately.

Chrome

  1. 4 - 105: Supported
  2. 106: Supported
  3. 107 - 109: Supported

Edge

  1. 12 - 104: Supported
  2. 105: Supported

Safari

  1. 3.1 - 15.6: Supported
  2. 16.0: Supported
  3. 16.1 - TP: Supported

Firefox

  1. 2 - 48: Not supported
  2. 49 - 104: Supported
  3. 105: Supported
  4. 106 - 107: Supported

Opera

  1. 9 - 12.1: Not supported
  2. 15 - 90: Supported
  3. 91: Supported

IE

  1. 5.5 - 10: Supported
  2. 11: Supported

Chrome for Android

  1. 105: Supported

Safari on iOS

  1. 3.2 - 15.6: Supported
  2. 16.0: Supported
  3. 16.1: Supported

Samsung Internet

  1. 4 - 17.0: Supported
  2. 18.0: Supported

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 64: Supported

UC Browser for Android

  1. 13.4: Supported

Android Browser

  1. 2.1 - 4.4.4: Supported
  2. 105: Supported

Firefox for Android

  1. 104: Supported

QQ Browser

  1. 13.1: Supported

Baidu Browser

  1. 13.18: Supported

KaiOS Browser

  1. 2.5: Not supported

A workaround for the lack of support in Firefox 31 - Firefox 48 is to use CSS variables. See this Stack Overflow answer for an example.

Resources:
Firefox implementation bug
MDN Web Docs - background-position-x
MDN Web Docs - background-position-y
Blog post on background-position-x & y properties