html,
body {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  background-color: #222;
  color: white;
  height: 100vh;
  max-height: 100vh;
  overflow: hidden;
  /* マウストレールに使う */
  cursor: none;
}

.background {
  position: absolute;
  display: block;
  top: 0;
  left: 0;
  z-index: 0;
  pointer-events: none;
}

#animated-text{
  margin: 200px 100px 0px 100px;
  font-size: 2rem;
}

#animated-text span {
  display: inline-block;
}

#confetti-button{
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%); 
  background-color: bisque;
  padding: 10px;
  font-size: 2rem;
  border: 0.5px solid black;
  border-radius: 20px;
  cursor: none;
  /* z-index: 5; */
}

.spark{
  position: absolute;
  width: 40px;
  height: 40px;
  transform: translate(0px, -20px);
}
.spark span{
  position: absolute;
  width: 2px;
  height: 20px;
  pointer-events: none;
  transform-origin: bottom;
  overflow: hidden;
  background: #0f0;
  filter: drop-shadow(0 0 20px #0f0) drop-shadow(0 0 40px #0f0);
}
.spark span::before{
  content: '';
  position: absolute;
  width: 100%;
  height: 100%;
  background: #0f0;
  transform: translateY(100%);

  animation: sparks 1s ease-in-out forwards;
}
/* ブラウザーによるアニメーションが動かない場合もあります。 */
@keyframes sparks
{
  0%
  {
    transform: translateY(100%);
  }
  100%
  {
    transform: translateY(0%);
  }
}

/* マウストレールエフェクト */
.trail{
  position: absolute;
  top: 0;
  left: 0;
  width: 20px;
  height: 20px;
  background-color: #fff;
  border-radius: 50%;
  pointer-events: none;
  will-change: transform, opacity;
  mix-blend-mode: screen;
}