Removing that ugly :focus ring (and keeping it too) from: https://hackernoon.com/removing-that-ugly-focus-ring-and-keeping-it-too-6c8727fefcd2

styles.css

body:not(.user-is-tabbing) {
    button:focus,
    input:focus,
    select:focus,
    textarea:focus {
        outline: none;
    }
}

userIsTabbing.js

function handleFirstTab(e) {
    if (e.keyCode === 9) {
        document.body.classList.add('user-is-tabbing');
        window.removeEventListener('keydown', handleFirstTab);
    }
}
window.addEventListener('keydown', handleFirstTab);