Can I use
?

background-position-x & background-position-y

- UNOFF

CSS longhand properties to define x or y positions separately.

IE

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

Edge

  1. 12 - 94: Supported
  2. 95: Supported

Firefox

  1. 2 - 48: Not supported
  2. 49 - 92: Supported
  3. 93: Supported
  4. 94 - 95: Supported

Chrome

  1. 4 - 94: Supported
  2. 95: Supported
  3. 96 - 98: Supported

Safari

  1. 3.1 - 14.1: Supported
  2. 15: Supported
  3. TP: Supported

Opera

  1. 9 - 12.1: Not supported
  2. 15 - 79: Supported
  3. 80: Supported

Safari on iOS

  1. 3.2 - 14.8: Supported
  2. 15: Supported

Opera Mini

  1. all: Not supported

Android Browser

  1. 2.1 - 4.4.4: Supported
  2. 94: Supported

Opera Mobile

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

Chrome for Android

  1. 94: Supported

Firefox for Android

  1. 92: Supported

UC Browser for Android

  1. 12.12: Supported

Samsung Internet

  1. 4 - 14.0: Supported
  2. 15.0: Supported

QQ Browser

  1. 10.4: Supported

Baidu Browser

  1. 7.12: 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