Can I use
?

CSS3 attr() function for all properties

- UNOFF

While attr() is supported for effectively all browsers for the content property, CSS Values and Units Level 5 adds the ability to use attr() on any CSS property, and to use it for non-string values (e.g. numbers, colors).

Chrome

  1. 4 - 107: Not supported
  2. 108: Not supported
  3. 109 - 111: Not supported

Edge

  1. 12 - 106: Not supported
  2. 107: Not supported

Safari

  1. 3.1 - 16.0: Not supported
  2. 16.1: Not supported
  3. 16.2 - TP: Not supported

Firefox

  1. 2 - 106: Not supported
  2. 107: Not supported
  3. 108 - 109: Not supported

Opera

  1. 9 - 91: Not supported
  2. 92: Not supported

IE

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

Chrome for Android

  1. 107: Not supported

Safari on iOS

  1. 3.2 - 16.0: Not supported
  2. 16.1: Not supported

Samsung Internet

  1. 4 - 18.0: Not supported
  2. 19.0: Not supported

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 72: Not supported

UC Browser for Android

  1. 13.4: Not supported

Android Browser

  1. 2.1 - 4.4.4: Not supported
  2. 107: Not supported

Firefox for Android

  1. 106: Not supported

QQ Browser

  1. 13.1: Not supported

Baidu Browser

  1. 13.18: 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