fixed grey background in banner

This PR aims at improve the UI's usability by simplifying filter buttons and a gentle facelift on page layout and fonts.  With this changes, all three top groups of data selection buttons are consolidated into a single line with equal distance between them.   Instead of being unbounded, the page layout is now fixed and centered.  Pie chart graph are touched to conform to the new page width.  Also the legend of chart graph is expanded to so the names top contributors don't often get wrapped round.