Hey Tuanphan,
We're having the exact same problem - we've tried all the codes put on here and some slightly work but not 100%, we'll get a white block at the top, a black gap at the bottom or it's resized and it's in the site header.
This is on our home page but we need it done to ALL our pages on the website. Can you help?
Website is: www.workout-wolf.co.uk