Can I use
?

CSS Environment Variables env()

- UNOFF

Usage of environment variables like safe-area-inset-top.

Chrome

  1. ❌ 4 - 68: Not supported
  2. ✅ 69 - 130: Supported
  3. ✅ 131: Supported
  4. ✅ 132 - 134: Supported

Edge

  1. ❌ 12 - 18: Not supported
  2. ✅ 79 - 130: Supported
  3. ✅ 131: Supported

Safari

  1. ❌ 3.1 - 10.1: Not supported
  2. ◐ 11: Partial support
  3. ✅ 11.1 - 18.0: Supported
  4. ✅ 18.1: Supported
  5. ✅ 18.2 - TP: Supported

Firefox

  1. ❌ 2 - 64: Not supported
  2. ✅ 65 - 131: Supported
  3. ✅ 132: Supported
  4. ✅ 133 - 135: Supported

Opera

  1. ❌ 9 - 55: Not supported
  2. ✅ 56 - 113: Supported
  3. ✅ 114: Supported

IE

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

Chrome for Android

  1. ✅ 131: Supported

Safari on iOS

  1. ❌ 3.2 - 10.3: Not supported
  2. ◐ 11: Partial support
  3. ✅ 11.3 - 18.0: Supported
  4. ✅ 18.1: Supported
  5. ✅ 18.2: Supported

Samsung Internet

  1. ❌ 4 - 9.2: Not supported
  2. ✅ 10.1 - 25: Supported
  3. ✅ 26: Supported

Opera Mini

  1. ❌ all: Not supported

Opera Mobile

  1. ❌ 10 - 12.1: Not supported
  2. ✅ 80: Supported

UC Browser for Android

  1. ✅ 15.5: Supported

Android Browser

  1. ❌ 2.1 - 4.4.4: Not supported
  2. ✅ 131: Supported

Firefox for Android

  1. ✅ 132: Supported

QQ Browser

  1. ✅ 14.9: Supported

Baidu Browser

  1. ✅ 13.52: Supported

KaiOS Browser

  1. ❌ 2.5: Not supported
  2. ✅ 3: Supported
Resources:
The env() CSS Function - MDN Web Docs
JSFiddle test case
Designing Websites for iPhone X - WebKit Blog