.topnav {
  background-color: #32CD32;
  overflow: hidden;
}

.topnav a {
  float: left;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 17px;
}


.topnav a:hover {
  background-color:green;
  color: black;
}


.topnav a.active {
    float: left;
  color: #f2f2f2;
  background-color:olivedrab;
}
body{
    background-color:lightgreen;
}

footer{
     background-color: #333;
  overflow: hidden; 
}

footer a{
    float: left;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 17px;
}
footer a:hover{
    background-color: #ddd;
  color: black;
}

footer a.active{
  float: left;
  color: #f2f2f2;  
}
table {
  font-family: arial, sans-serif;
  border-collapse: collapse;
  width: 100%;
}

td, th {
  border: 1px solid #dddddd;
  text-align: left;
  padding: 8px;
}

tr:nth-child(even) {
  background-color: #dddddd;
}