This is an area under great demand, but crippled by browsers for some time (specifically IE).
As technology advances, so do the browsers and their rendering of programming, scripts, and css. To date, IE seems to have fallen the farthest behind, however IE9 appears to provide light at the end of the tunnel. Furthermore, corners and shadows have been somewhat experimental, with several browsers using their own mark-up to achieve the desired results. In the end, unified standards are beginning to emerge.
Would you like to achieve the following?
Wait, that was so simple, I really have no need of continuing the post! As demonstrated above, I have shared the actual css needed to achieve.
Again, IE is lagging, but many sites are beginning to implement this visual effect now.
