Redesign overlay

The overlay is the main thing I want redesigned. Right now, there is an overlay on three instances, 1. when post is clicked on, lightbox opens to show post. 2. when clicking the + button, the posting form opens. 3. when clicking the edit button on an existing post, the lightbox closes and the posting form opens. What I need 1. When the overlay opens, the homepage stays exactly where it is, and when it closes, the homepage is still where it is before. Essentially it doesn't move at all. 2. When overlay is opened, there will always be only one main scrollbar on the side of the page that will scroll the overlay page (not the homepage). Even if there's nothing to scroll, it will still be there. 3. When the posting form or lightbox is smaller than the height of the screen, it should be appear in the middle of the screen. When the posting form or lightbox is bigger than the height of the screen, the top of the posting form or lightbox should start at the top of the page (not the middle). 4. Move through posts within the overlay without exiting and without the loading sign there. This is the same when editing a post, the overlay should not close and open again, instead it should smoothly transition from the post to the editing form. 5. Is it possible to open the post lightbox immediately? Right now, its a bit slow to load, taking almost 3 seconds. If you need any clarification, let me know. Please provide me with a quote. Cheers, Muhammad