animated-footer.css

.wave {
  position: absolute;
  top: -100px;
  left: 0;
  width: 100%;
  height: 100px;
  background: url("pictures/wave.png");
  background-size: 1000px 100px;
}

.dark-mode .wave {
  filter: brightness(0) invert(1);
}

.wave#wave1 {
  z-index: 1000;
  opacity: 1;
  bottom: 0;
  animation: animateWaves 10s linear infinite;
}

.wave#wave2 {
  z-index: 999;
  opacity: 0.4;
  bottom: 10px;
  animation: animate 9s linear infinite !important;
}

.wave#wave3 {
  z-index: 1000;
  opacity: 0.2;
  bottom: 15px;
  animation: animateWaves 7s linear infinite;
}

.wave#wave4 {
  z-index: 999;
  opacity: 0.6;
  bottom: 20px;
  animation: animate 9s linear infinite;
}

@keyframes animateWaves {
  0% {
    background-position-x: 1000px;
  }
  100% {
    background-positon-x: 0px;
  }
}

@keyframes animate {
  0% {
    background-position-x: -1000px;
  }
  100% {
    background-positon-x: 0px;
  }
}