header {position: fixed;
        top: 0;            
		left: 0;            
		width: 100%;           
		background-color: #f8f9fa;            
		padding: 10px;            
		text-align: center;            
		z-index: 1000;        
		}        
		footer {
                position: fixed;
				bottom: 0;          
				left: 0;            
				width: 100%;           
				background-color: #f8f9fa;       
				padding: 10px;         
				text-align: center;       
				}        
		main {     
				margin-top: 0px;   
				margin-bottom: 40px;   
				}
				 a{
 				       color: #000;
  				       text-transform: uppercase;
  				       text-decoration: none;
  				       display: inline-block;
  				       padding: 5px 10px;
 				       position: relative;
 				       }

 				    a:after{    
  				            background: none repeat scroll 0 0 transparent;
  				            bottom: 0;
   				            content: "";
   				            display: block;
   				            height: 2px;
   				            left: 50%;
   				            position: absolute;
   				            background: #5db616;
   				            transition: width 0.3s ease 0s, left 0.3s ease 0s;
   				            width: 0;
  				           }

                    a:hover:after{ 
   				                  width: 100%; 
   				                  left: 0; 
  				                 }