<div class="bubble-1 bubble-container anim bubble-animation-x">
  <div class="bubble bubble-animation-y"></div>
</div>

<div class="bubble-2 bubble-container anim bubble-animation-x">
  <div class="bubble bubble-animation-y"></div>
</div>

<div class="bubble-3 bubble-container anim bubble-animation-x">
  <div class="bubble bubble-animation-y"></div>
</div>

<div class="bubble-4 bubble-container anim bubble-animation-x">
  <div class="bubble bubble-animation-y"></div>
</div>

<div class="bubble-5 bubble-container anim bubble-animation-x">
  <div class="bubble bubble-animation-y"></div>
</div>

body{
  background-color:turquoise;
}

.bubble-1 {
  left: 300px;
  animation-delay: 1.3s;
}
.bubble-1 .bubble-animation-y{
  animation-delay: 0.7s;
}

.bubble-2 {
  left: 33px;
  animation-delay: 2s;
}
.bubble-2 .bubble-animation-y{
  animation-delay: 2.1s;
}

.bubble-3 {
  left: 225px;
  animation-delay: 4.7s;
}
.bubble-3 .bubble-animation-y{
  animation-delay: 3.8s;
}

.bubble-4 {
  left: 285px;
  animation-delay: 0s;
}
.bubble-4 .bubble-animation-y{
  animation-delay: 6s;
}

.bubble-5 {
  left: 115px;
  animation-delay: 1.5s;
}
.bubble-5 .bubble-animation-y{
  animation-delay: 7s;
}

.bubble-container {
  position: absolute;
  width: 25px;
  height: 25px;
  bottom: 0;
}

.bubble {
  background-color: #ff00ff;
  opacity: 0;
  border-radius: 100%;
  width: 25px;
  height: 25px;
  box-shadow: 0 20px 30px rgba(0, 0, 0, 0.2), inset 0px 10px 30px 5px rgba(255, 255, 255, 1);
}

.bubble-animation-x {
  animation-duration: 2s;
  animation-iteration-count: infinite;
  animation-name: bubbleXAnimFrames;
  animation-timing-function: ease;
  animation-direction: alternate;
}

.bubble-animation-y {
  animation-duration: 6s;
  animation-iteration-count: infinite;
  animation-name: bubbleYAnimFrames;
  animation-timing-function: linear;
}

@keyframes bubbleXAnimFrames {
  0% {
    transform: translateX(0);
  }
  100% {
    transform: translateX(50px);
  }
}

@keyframes bubbleYAnimFrames {
  0% {
    transform: translateY(0);
    opacity: 0;
  }
  10% {
    transform: translateY(0);
    opacity: 0.5;
  }
  95% {
    transform: translateY(-280px);
    opacity: 0.5;
  }
  100% {
    transform: translateY(-300px);
    opacity: 0;
  }
}