Is there a website with responsive design, you want to make the block as follows:
when the screen width 360 height was 250px, the width of the entire screen.
when the screen width, 650 height was 450px width to full screen.
when you change the screen width from 650 to 360, to the height of the block gradually changed from 250px to 450px, for example when the screen width, 600 height of the block was approximately 410px.
When you change the width of the screen more than 650 - to maintain altitude 450 and align the unit in the center.