body {
  background-color: lightGray;
  color: red;
  font-family: Arial, Helvetica, sans-serif;
  text-align: center;
  margin-top: 50px;
}
.next_step {
  color: darkGreen;
  font-size: 22px;
  }
.aufgabe {
  color: #39ff14;
  background-color: darkRed;
  border-style: dotted dotted dotted dotted;
  border-width: 2px 2px 2px 2px;
  padding: 10px 10px 10px 10px;
  border-radius: 5px;
}
.link {
  position: relative;
  left: 300px;
  bottom: 20px;
  border-style: solid solid solid solid;
  border-width: 5px;
  padding: 17px;
  background-color: #13B5ED;
  color: #c27e00;
  border-radius: 15px 15px 15px 15px;