消えていく幻影

.phantom {
  display: inline-block;
  padding: 10px 20px;
  background: purple;
  color: white;
  margin: 5px;
  border-radius: 8px;
}

const btn = document.querySelector('#summonBtn');
const stage = document.querySelector('#stage');

btn.addEventListener('click', function() {
  const phantom = document.createElement('div');
  phantom.textContent = '👻 幻影';
  phantom.classList.add('phantom');
  stage.appendChild(phantom);

  setTimeout(function() {
    phantom.remove();
  }, 2000);
});