/* reset */

    body {
     background-color: lightblue;
     background: linear-gradient(135deg, #1F9FFF, white 50%, #1F9FFF);
     margin: 0px;
     padding: 0px;
     font-family: Verdana, sans-serif;
     font-size: 0.8em;
     line-height: 1.5;
     
    }



    div#main {
     width: 950px;
     margin: 2em auto;
     border: 1px solid gray;
     background-color: #ffffff;
     border-radius: 30px;                    /* zaoblene rohy */
     box-shadow: 0px 0px 20px gray;          /* stin boxu */

     }   

    header {
      background-color: lightblue;
      background: linear-gradient(135deg, #1F9FFF, white 50%, #1F9FFF);
      padding: 50px;          
      text-align: center;
      border-radius: 30px;
      border-bottom: solid 1px gray;
    
     }
     
    nav {
     float: left;
     width: 200px;
     padding: 20px;
     margin: 0px;
     text-align: center;

     }

    section {
     margin-left: 240px;
     padding: 20px;
     border-left: solid 1px gray;
     text-align: justify;

     }

    footer {
     padding: 20px;
     text-align: center;
     border-top: solid 1px gray;
     clear: both;

     }

     li {
      list-style-type: none;
     
     }