.books-tag2 {
    padding: 2px 6px;
    border-style: solid;
    border-width: 0 0 2px 0;
    border-color: #287292;
    margin-bottom: 16px;
    display: inline-block;
    opacity: 0.9;
    filter: alpha(opacity=90);
    color: #ffffff;
    background-color: #3294BD;
}

.books-tag2:hover {
    opacity: 0.8;
    filter: alpha(opacity=100);
    border-color: #3294BD;
}

.mb-1{
  margin-bottom: 1em;
}

.mb-2{
  margin-bottom: 2em;
}

.mb-3{
  margin-bottom: 4em;
}

.mb-4{
  margin-bottom: 8em;
}

.mb-5{
  margin-bottom: 10em;
}