.wp-block-calendar table th{
    background: transparent;
}
.wp-block-calendar tfoot a{
    color: inherit;
    text-decoration: none;
}
.wp-block-calendar #prev{
    text-align: left;
}
.wp-block-calendar #next{
    text-align: right;
}
.wp-block-calendar table th,
.wp-block-calendar tbody td, .wp-block-calendar th{
    text-align: center;
}
.wp-block-calendar table{
    border: none;
    border-collapse: collapse;
}
#wp-calendar thead th{
    padding: 10px;
    font-size: 14px;    
}