Can I use
?

Scoped CSS

- UNOFF

Allows CSS rules to be scoped to part of the document, based on the position of the style element. The attribute has been removed from the current specification.

Chrome

  1. 4 - 19: Not supported
  2. 20 - 36: Disabled by default
  3. 37 - 110: Not supported
  4. 111: Not supported
  5. 112 - 114: Not supported

Edge

  1. 12 - 110: Not supported
  2. 111: Not supported

Safari

  1. 3.1 - 16.2: Not supported
  2. 16.3: Not supported
  3. 16.4 - TP: Not supported

Firefox

  1. 2 - 20: Not supported
  2. 21 - 54: Supported
  3. 55 - 60: Disabled by default
  4. 61 - 110: Not supported
  5. 111: Not supported
  6. 112 - 113: Not supported

Opera

  1. 9 - 94: Not supported
  2. 95: Not supported

IE

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

Chrome for Android

  1. 111: Not supported

Safari on iOS

  1. 3.2 - 16.2: Not supported
  2. 16.3: Not supported
  3. 16.4: Not supported

Samsung Internet

  1. 4 - 19.0: Not supported
  2. 20: Not supported

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 73: Not supported

UC Browser for Android

  1. 13.4: Not supported

Android Browser

  1. 2.1 - 4.4.4: Not supported
  2. 111: Not supported

Firefox for Android

  1. 110: Not supported

QQ Browser

  1. 13.1: Not supported

Baidu Browser

  1. 13.18: Not supported

KaiOS Browser

  1. 2.5: Supported
  2. 3: Not supported
Resources:
Firefox bug #1291515: disable `<style scoped>` in content documents
HTML5Rocks article
Polyfill
HTML5 Doctor article