Screen Rotation for Mobile

Hey guys, I have a quick question. I have a lightbox on my landing page into which I have embedded a pdf slide deck for my company. It works really well, except that on the mobile version of the site, the pdf is small at screen width (portrait).

Is there a way (JS/CSS/Other) in which I can automatically force the screen into rotation when somebody pushes the lightbox button for that particular lightbox so that the pdf can be view in landscape mode?

“It’s the little things…” I know!! :rofl: