body {
  font-family: sans-serif;
  background: #fdfdfd;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
}

.container {
  box-shadow: -1px 6px 88px -2px rgba(0, 0, 0, 0.35);
  padding: 200px;
  border-radius: 10px;
}

#box {
  width: 100px;
  height: 100px;
  background: teal;
  margin-top: 100px;
  margin-left: -200px;
}

button {
  outline: none;
  padding: 10px;
  font-size: 1rem;
  cursor: pointer;
}

button:active {
  transform: scale(0.98);
}

.calculate-btn {
  margin-left: 15px;
}

#box.animate {
  animation: animate;
  animation-duration: 1s;
  animation-timing-function: ease-in-out;
  animation-direction: alternate;
  animation-iteration-count: infinite;
}

@keyframes animate {
  0% {
    transform: translateX(0);
  }

  100% {
    transform: translateX(500px);
  }
}