How to reset / remove chrome's input highlighting / focus border?

You should be able to remove it using

outline: none;

but keep in mind this is potentially bad for usability: It will be hard to tell whether an element is focused, which can suck when you walk through all a form's elements using the Tab key - you should reflect somehow when an element is focused.

I had to do all of the following to completely remove it:

outline-style: none;
box-shadow: none;
border-color: transparent;

Example:

button {
  border-radius: 20px;
  padding: 20px;
}

.no-focusborder:focus {
  outline-style: none;
  box-shadow: none;
  border-color: transparent;
  background-color: black;
  color: white;
}

<p>Click in the white space, then press the "Tab" key.</p>
<button>Button 1 (unchanged)</button>
<button class="no-focusborder">Button 2 (no focus border, custom focus indicator to show focus is present but the unwanted highlight is gone)</button>
<br/><br/><br/><br/><br/><br/>

To remove the default focus, use the following in your default .css file :

:focus {outline:none;}

You can then control the focus border color either individually by element, or in the default .css:

:focus {outline:none;border:1px solid red}

Obviously replace red with your chosen hex code.

You could also leave the border untouched and control the background color (or image) to highlight the field:

:focus {outline:none;background-color:red}

:-)