CSSでぷかぷか浮かぶタイトル

#CSSでぷかぷか浮かぶタイトルを作りたい！

//css
.title,
.title span {
  position: relative;
  display: inline-block;
}
.title span {
  padding: .65em 4em;
  background: -webkit-linear-gradient(#fe5f95 , #ff3f7f);
  background: linear-gradient(#fe5f95 , #ff3f7f);
  border: 1px solid #fe3276;
  border-radius: 4px;
  color: #fff;
  box-shadow: 10px 10px 15px -10px;
  /* text-decoration: none; */
  text-align: center;
  animation: 3s float ease-in-out infinite;
  animation: 3s float ease-in-out infinite;
}
.title::after {
  position: absolute;
  bottom: -15px;
  left: 50%;
  z-index: -1;
  content: '';
  width: 100%;
  height: 24px;
  background-color: rgba(0, 0, 0, 0.3);
  box-shadow: 10px 10px 15px -10px;
  border-radius: 50%;
  transform: translateX(-50%);
  transform: translateX(-50%);
  animation: 3s shadow ease-in-out infinite;
  animation: 3s shadow ease-in-out infinite;
}
@-webkit-keyframes float {
  50% {
    transform: translateY(-10px);
  }
}
@keyframes float {
  50% {
    transform: translateY(-10px);
  }
}
@-webkit-keyframes shadow {
  50% {
    width: 70%;
    height: 18px;
  }
}
@keyframes shadow {
  50% {
    width: 70%;
    height: 18px;
  }
}

//HTML
 <h1 class="title"><span>タイトル</span></h1>