However, when I visit the site for the first time the main menu's background image doesn't show up. Instead, the page is black for 10-15 seconds (when I view it in a Firefox browser on my Galaxy smartphone, it never changes from black). On my desktop Firefox browser, the main menu's background image eventually shows up and from that point on there is no problem.
I am guessing that the problem stems from the fact that the page features a video and an extensive virtual tour, both of which are pretty large in size. My objective was to fade the main menu image when either the video or virtual tour buttons are selected, revealing the applicable content below. Does anyone have a suggestion on how to tweak this to make the main menu image and buttons show up faster?