embed and attached files issues

Thank you, @Tom 

Note on code - my wp said was error. I think it should be this way for @media section as was missing definition for what style is:

@media screen and (max-width: 420px) {#wpforo-wrap .wpforo-post-content .wpf-video, #wpforo-wrap .wpforo-post-content .wpf-video iframe {height: 200px !important;}}

Thank you again.

Correct code with improved alignment and for full iFrame to render properly needs 340px instead of 300px and at least for my CSS 0px margin-left.:

/*wpfor fix for video auto size*/
#wpforo-wrap .wpforo-post-content .wpf-video, #wpforo-wrap .wpforo-post-content .wpf-video iframe {
max-width: 100% !important;
width: 100% !important;
height: 340px !important; 
margin-left: 0!important;
}
@media screen and (max-width: 420px) {#wpforo-wrap .wpforo-post-content .wpf-video, #wpforo-wrap .wpforo-post-content .wpf-video iframe {height: 200px !important;}}