.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 caption{
    text-align: center;
    caption-side: top;    
}

.wp-block-calendar tfoot tr td{
    border: none;
}