html, body{
  margin: 0;
  padding:0;
  height: 100%;
  width: 100%;
  overflow-x: hidden;
  overflow-y: auto;
  
} body {
  background-color: lightblue;
  display: flex;
  flex-direction: column;
  align-items: center;
  
}

.content{
  flex: 1;
  display: flex;
  flex-direction: column;
}

.header, .topnav, .column, .footer {
    box-sizing: border-box;
    width: 80%;
    padding: 20px;
    max-width: 1200px;
    margin-left: auto; 
    margin-right: auto; 
  
  }

.header, .footer{
  text-align: center;
}

  .topnav{
    text-align: center;
  }

  .topnav a {
    color:black;
    text-decoration: none;
    margin: 0 10px;
    
  }
  

  .topnav a:hover {
    color: purple;
  }

 
.column {
    text-align: center;
    flex-grow: 1;  
  }
  
  /* Clear floats after the columns */
  .row::after {
    content: "";
    display: table;
    clear: both;
  }