div.top_nav a:link {color: white; text-decoration: none; }
div.top_nav a:visited {color: white; text-decoration: none; }
div.top_nav a:hover {color: white; text-decoration: underline; }
div.top_nav a:active {color: blue; }

div.bottom_nav a:link {color: black; text-decoration: none; }
div.bottom_nav a:visited {color: black; text-decoration: none; }
div.bottom_nav a:hover {color: black; text-decoration: underline; }
div.bottom_nav a:active {color: red; } 

li:hover {
  text-decoration: underline; 
}