Button active style with keyboard

by Thomas ZILLIOX

HTML

<button type="submit">Click me and I give you a!</button>

CSS

button:focus {
    outline: 1px dotted grey;
}

button:active {
    outline-width: 5px
}

JavaScript

var buttons = document.getElementsByTagName('button');
for (var i=0; i<buttons.length; i++) {
    buttons[i].onclick = function(e){
        this.innerHTML += '!'
    }
}