.delta-video-wrap { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; border-radius: var(--delta-radius); }
.delta-video-wrap iframe { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }
.delta-lesson-content { font-size: var(--delta-fs-lg); line-height: 1.7; }