water.css

#water__level {
  background-color: #626262;
  -webkit-mask-image: url(water_mask2.png);
  mask-image: url(water_mask2.png);
  -webkit-mask-size: 100% 100%;
  mask-size: 100% 100%;
  -webkit-mask-repeat: no-repeat;
  mask-repeat: no-repeat;
  position: relative;
  overflow: hidden;
}

.water__level__container,
.cap__container {
  --total-water: 4;
  --current-water: 4;
  --water-height: calc(85% - 83% * var(--current-water) / var(--total-water));
  width: 100%;
  height: 100%;
  background-image: url("water.png");
  background-size: 400% 100%;
  background-repeat: repeat-x;
  filter: invert(52%) sepia(96%) saturate(329%) hue-rotate(170deg)
    brightness(91%) contrast(103%);
  animation: moveWater 5s linear infinite;
  position: absolute;
  top: var(--water-height);
  left: 0;
  transition: 0.2s;
  /* display: flex; */
  /* align-items: center; */
  /* justify-content: center; */
  /* text-align: center; */
  /* font-size: 5rem; */
  /* color: black; */
  /* font-family: 'LHR Firehouse'; */
}

.cap__container {
  background-image: url("x.png");
  background-size: 100% 100%;
  background-repeat: no-repeat;
  filter: none;
  animation: none;
  position: absolute;
  top: 0%;
  left: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 5rem;
  color: white;
  font-family: "LHR Firehouse";
  padding-left: 10px;
}

@keyframes moveWater {
  0% {
    background-position: 0 0;
  }
  100% {
    background-position: -400% 0;
  }
}