media.css

@media screen and (max-width: 1200px){
  .headerSection {
    width: 90%;
    margin: 20px 5% 10px 5%;
    background-position: center center;
    float: none;
    background-size: cover;
    height: 300px;
  }
  .quizSection {
    width: 90%;
    float: none;
    margin: 20px 5% 10px 5%;
  }
  .tablet {
    display: block;
  }
  .headline {
      text-align: center;
      font-size: 2em;
      margin-top: 14px;
  }
}

@media screen and (max-width: 900px){
  #submit {
    width: 100%;
    padding: 10px;
  }
}

@media screen and (max-width: 500px){
  .headerSection {
    height: 150px;
  }
  .quizWrapper {
    width: 100%;
    margin: 0px;
    border: 0px;
    -webkit-box-shadow: none;
    -moz-box-shadow: none;
    box-shadow: none;
    }
  }
}