.single-stm-lessons .entry-header,
.single-stm-lessons .col-lg-3.col-md-3.hidden-sm.hidden-xs {
    display: none;
}

.single-stm-lessons .col-lg-9.col-md-9.col-sm-12.col-xs-12 {
    float: none;
    max-width: 960px;
    width: 100%;
    margin: 0 auto;
}