a:visited, a:link {
    color: black;
}


a:hover {
    text-decoration: none;
    color: gray;
}

.center {
    text-align: center;
}

.table-striped > tbody > tr:nth-child(2n+1) > td, 
.table-striped > tbody > tr:nth-child(2n+1) > th {
   background-color: #DCDCDC;
}

button {
    margin-top: 500;
}

.header-text {
    color: black;
}