td {
  border: solid 1px white;
  padding: 5px;
}

.wave {
  width: 100%;
  height: 200px;
  background-color: #ccc;
  position: relative;
  overflow: hidden;
}

.wave::before {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: #fff;
  animation: waveAnimation 4s linear infinite;
}

@keyframes waveAnimation {
  0% {
    transform: translateY(0);
  }
  100% {
    transform: translateY(-100%);
  }
}
