Android browser - remove outline border when anchor is focused

Set the CSS property -webkit-tap-highlight-color as follows:

* { -webkit-tap-highlight-color: rgba(0,0,0,0); }

Note: setting the color in other ways usually fails because of the way webkit renders the highlight. Depends on version/variant according to my experience.

according to this post it's better to use

a:focus,
button:focus,
input:focus,
textarea:focus {
    outline: none;
}