.navbar {
    overflow: hidden;
    background-color: darkgreen;
    position: fixed; 
    top: 0; 
    height: 100px;
    width: 100%; 
  }
  
  .navbar a {
    float: left;
    display: block;
    color: #f2f2f2;
    text-align: center;
    font-size: 25px;
    padding: 40px 20px;
    text-decoration: none;
  }
  
  .navbar a:hover {
    background: #ddd;
    color: black;
  }
  
  .main {
    margin-top: 120px; 
    margin-left: 20px;
  }

  @media screen and (min-width: 0px) and (max-width: 600px) {
      .navbar{writing-mode: vertical-rl}
      .main{writing-mode: vertical-rl;
    float:right;
font-size: 25px}
      .navbar a {padding: 10px 20px;}
  }

  @media screen and (min-width: 601px) and (max-width: 1000px) {
   .navbar{
        list-style-type: none;    
        margin: 0;
        padding: 0;
        max-width: 15%;
        background-color: darkgreen;
        height: 100%;
        position: fixed; 
        overflow: auto;}
    .main{ 
        position:relative;
        margin-left: 200px;
    font-size: 30px}
   }