Can I use
?

CSS3 attr() function for all properties

- CR

While attr() is supported for effectively all browsers for the content property, CSS Values and Units Level 3 adds the ability to use attr() on any CSS property, and to use it for non-string values (e.g. numbers, colors).

IE

  1. 5.5 - 10: Not supported
  2. 11: Not supported

Edge

  1. 12 - 93: Not supported
  2. 94: Not supported

Firefox

  1. 2 - 92: Not supported
  2. 93: Not supported
  3. 94 - 95: Not supported

Chrome

  1. 4 - 93: Not supported
  2. 94: Not supported
  3. 95 - 97: Not supported

Safari

  1. 3.1 - 14.1: Not supported
  2. 15: Not supported
  3. TP: Not supported

Opera

  1. 9 - 79: Not supported
  2. 80: Not supported

Safari on iOS

  1. 3.2 - 14.8: Not supported
  2. 15: Not supported

Opera Mini

  1. all: Not supported

Android Browser

  1. 2.1 - 4.4.4: Not supported
  2. 94: Not supported

Opera Mobile

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

Chrome for Android

  1. 94: Not supported

Firefox for Android

  1. 92: Not supported

UC Browser for Android

  1. 12.12: Not supported

Samsung Internet

  1. 4 - 14.0: Not supported
  2. 15.0: Not supported

QQ Browser

  1. 10.4: Not supported

Baidu Browser

  1. 7.12: Not supported

KaiOS Browser

  1. 2.5: Not supported

See the generated content table for support for attr() for the content property.

Resources:
Chromium issue #246571: Implement CSS3 attribute / attr references
WebKit Bug #26609: Support CSS3 attr() function
Mozilla Bug #435426: implement css3-values extensions to `attr()`
MDN Web Docs - CSS attr
Microsoft Edge feature request on UserVoice