How about for buttons to reset the :focus and user-select?

[kaaboeld]

button{
  user-select:none;
}
button:focus{
  outline:0;
}

[filipelinhares]

Thanks for your suggestion @kaaboeld.

button:focus {
  outline: 0;
}

Outline on focus is very important for keyboard users, low-sighted users, and other accessibility technology. We won't add this.

---

button {
  user-select:none;
}

"Is user-select: none bad UX?".

This sounds good.

I'll keep this issue open for feedback.

[kaaboeld]

visible :focus for keyboard users is imprtaint, but this style displayed in different browsers on different. If "ress" for reset it should just be cleaned, so that developers can make their own styling.

[filipelinhares]

Many developers just don't care about accessibility. Because of it browsers adding a minimal accessibility style.

The HTML5 specification has the following to say about removing the default outline:

“…if an alternative focusing style isn’t made available instead, the page will be significantly less usable > for people who primarily navigate pages using a keyboard, or those with reduced vision who use focus > outlines to help them navigate the page.”

Good read about it
outlinenone.com