When you use Divi Builder to edit a Learndash course page, by default the visual builder is only available on a relatively small part of the page, like so:

Make the Course Page Layout Fullwidth using Divi Learndash Kit
Divi Learndash Kit adds a "Fullwidth" option to the Page Layout setting shown below:

Setting the Page Layout to Fullwidth now makes the visual builder available for the full width of the page.
Make the Course Page Layout Fullwidth using CSS,
For the Learndash course pages we can make the Divi Builder layout full-width by hiding the other elements on the page / removing some excess padding. This can be achieved with the following CSS code:
.single-sfwd-courses .et_post_meta_wrapper,
.single-sfwd-courses #sidebar,
.single-sfwd-courses #main-content .container:before,
.single-sfwd-courses .learndash_post_sfwd-courses br,
.single-sfwd-courses #learndash_course_status {
display: none !important;
}
.single-sfwd-courses #left-area,
.single-sfwd-courses #main-content .container {
padding: 0 !important;
margin:0 !important;
width: 100% !important;
max-width: 100%;
}
Related Post: Adding CSS to the Divi Theme
Thanks guys
Thanks a lot for an awesome tip