* {
    box-sizing: border-box;
  }
  
  .menu {
    float: left;
    width: 20%;
    text-align: center;
  }
  
  .menu a {
    background-color: black;
    padding: 8px;
    margin-top: 7px;
    display: block;
    width: 100%;
    color: white;
  }
  
  .main {
    float: left;
    width: 60%;
    padding: 0 20px;
    text-align: left;
  }
  
  .right {
    background-color:black;
    float: left;
    width: 20%;
    padding: 15px;
    margin-top: 7px;
    text-align: center;
  }
  
  a {
    text-decoration: none;
    color: white
  }

  a:visited {
    color: white;
    background-color: transparent;
    text-decoration: none;
  }
  
  
  @media only screen and (max-width: 620px) {
    /* For mobile phones: */
    .menu, .main, .right {
      width: 100%;
    }
  }