body {
  margin: 0px;
  font-family: sans-serif;
}

.einleitung {
  text-align: center;
  margin-top: 25px;
}

.auswahl {
  display: flex;
  justify-content: space-around;
  align-items: center;
  flex-wrap: wrap;
}
  .ziele {
    width: 150px;
    height: auto;
    background-color: royalblue;
    padding: 5px;
    color: white;
    border-radius: 3px;
    margin: 5px;
  }

  button {
    border: 1px solid;
    padding: 4px 8px 4px 8px;
    border-radius: 5px;
    background-color: white;
    color: black;
    border-color: navy;
  }

  a{
    text-decoration: none;
    color: black;
  }

iframe{
  border: none;
  width: 100%;
  height: 1500px;
}