body {
  font-family: sans-serif;
  text-align: center;
}

#cups {
  position: relative;
  width: 700px;
  height: 160px;
  margin: 30px auto;
}

.cup {
  position: absolute;
  width: 100px;
  height: 120px;
  background: #eee;
  border: 2px solid #555;
  border-radius: 0 0 40px 40px;
  font-size: 36px;
  line-height: 120px;
  transition: left 1.2s ease;
}