Semakin bola cuba menstabilkan papan & selagi bola bergolek ke sana sini tak reti nak cari titik tengah graviti, selagi itulah papan alas terjongkang-jongkit

Demo

<div class="labu">
<div class="papan">
  <div class="bola"></div>
</div>
  </div>
<style>
  .labu {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 60vh;
  background: #0081cb33;
}
.bola {
  position: relative;
  bottom: 100px;
  left: calc(100% - 70px);
  width: 100px;
  height: 100px;
  background: #200022;
  border-radius: 50%;
  animation: bolagrk 2s ease-in-out 1.5s infinite alternate;
}
.bola::after {
  position: absolute;
  content: '';
  top: 50px;
  right: 10px;
  width: 10px;
  height: 10px;
  background: #fff;
  border-radius: 50%;
}
.papan {
  width: 500px;
  height: 25px;
  background: linear-gradient(45deg, #666, #444, #888, #aaa, #ccc) fixed;
  border-radius: 30px;
  transform: rotate(-15deg);
  filter: drop-shadow(20px 10px 4px gray);
  animation: naikt 2s ease-in-out 1.5s infinite alternate;
}
  @media screen and (max-width: 600px) {
.bola {
  position: relative;
  bottom: 80px;
  width: 80px;
  height: 80px;
    }
  }
@keyframes naikt {
  from {transform: rotate(-15deg);}
  to {transform: rotate(15deg);}
}
@keyframes bolagrk {
  from {left: calc(100% - 70px); transform: rotate(360deg);}
  to {left: calc(0% - 35px); transform: rotate(0deg);}
}
</style>

Rujukan CSS di codepen.io/aniketkudale/full/GREgYXy