Discussion on: 53 Things I Learned Writing a Multiplayer Strategy Game in Javascript and Python

The outline property itself isn't the critical bit. A distinct, accessible focus state is. So you could fake them:

input:focus {
  outline: 0;
  box-shadow: 0 0 0 3px #bfe7f3;
}

Only down-side to this technique is you generally need to then pay attention to the focus appearance for anything else in the app that receives focus so they all match.

Hope that's helpful and not just a noise-comment for what is a very awesome article! :)