changeDisplay.js

var authenticated = false
var userAuthData = null
function handleAuthentication (authData) {
  document.getElementById('accessContainer').style.display= 'none'
  document.getElementById('questionsContainer').style.display= 'block'
  authenticated = true
  userAuthData = authData
  document.getElementById('userName').innerHTML = authData.user.displayName
}

display.css

#questionsContainer {
  display: none;
}