table, th, td {  
    border: 3px solid white;  
    border-collapse: collapse;  
}  
th, td {  
    padding: 5px;  
}  
table#alter1 tr {  
    background-color: whitesmoke;  
}  
 
table#alter1 th { 
    width: 15%;
    color: white;  
    background-color: lightgreen;
    
     
}