<style>
    /* Remove the navbar's default margin-bottom and rounded borders */ 
    .navbar {
      margin-bottom: 0;
      border-radius: 0;
    }
    
    /* Set height of the grid so .sidenav can be 100% (adjust as needed) */
    .row.content {height: 450px}
    
    /* Set gray background color and 100% height */
    .sidenav {
      padding-top: 20px;
      background-color: #f1f1f1;
      height: 100%;
    }
    
    /* Set black background color, white text and some padding */
    footer {
      background-color: #555;
      color: white;
      padding: 15px;
    }
    
    /* On small screens, set height to 'auto' for sidenav and grid */
    @media screen and (max-width: 767px) {
      .sidenav {
        height: auto;
        padding: 15px;
      }
      .row.content {height:auto;} 
    }


.bg-dark {
    background-color: #343a40!important;
}


.center {
  display: block;
  margin-left: auto;
  margin-right: auto;
  width: 50%;
}


body {
  font-size:16px;
}

  </style>