Another great way to emphasize an object is to give it a box shadow. To do this you specify a horizontal and vertical offset from the object, the amount of blurring to add to the shadow, and the color to use, like this: box-shadow: 15px 15px 10px #888;
The two instances of 15px specify the vertical and horizontal offset from the element, and these values can be negative, 0 or positive. The 10px specifies the amount of blurring, with smaller values resulting in less blurring. And the #888 is the color for the shadow, which can be any valid color value.
Although the property name is called box-shadow, rounded borders are also taken into account, even to the extent that when an element is made circular, the shadow will follow that curve, so you are not restricted to simple, rectangular box shadows.