Center a Div:  the CSS Style must have a width and auto margins on the left and right.

For instance, #container {width: 1000px; margin: 0 auto;} 

(note:  margin: 0 auto; is a shortcut way of saying top & bottom margin is zero, right & left margin is auto.)

CSS3 border-radius property:  used to round corners of elements without images.

CSS3 box-shadow property: used to add a drop shadow to a box.

To learn more about CSS3, Watch the Video below, and then go to CSS3 Tutorials.