I'm trying to use the default WordPress youtube shortcode to resize an embedded video on a single Project page.
When using the code: [youtube https://www.youtube.com/watch?v=PGHonvREHVU&rel=0&w=320 ] all of the specific variables such as rel=0 are working as expected, but the resizing options are not working. If I do a shift-refresh on the page I can see that the video begins to load at the size passed from the shortcode, but it is then enlarged at some point by something the theme is doing.
Can you point me to where I can make changes to the theme so that I can stop this behavior or use a function of the theme instead to embed resized YouTube videos?