​

​

var observations = 0;

function logTransition() {

  if (!observations) {

    return;

  }

  observations--;

  var style = window.getComputedStyle(target, null);

  var value = style.getPropertyValue('visibility')

  + ' - '

  + style.getPropertyValue('background-color');

  console.log(value);

  requestAnimationFrame(logTransition);

}

​

var button = document.getElementById('start');

var target = document.getElementById('target');

start.addEventListener('click', function(){

  observations = 4;

  target.classList.toggle('started');

  logTransition();

});