border smmoth code example

Example 1: css border top

.topBorder {
  /*        width style color  */
  border-top: 5px solid black;
}

Example 2: css feather border

-moz-box-shadow: 1px 2px 3px rgba(0,0,0,.5);
-webkit-box-shadow: 1px 2px 3px rgba(0,0,0,.5);
box-shadow: 1px 2px 3px rgba(0,0,0,.5);

/* From further on in the answer:
1px: Horizontal offset of the effect. Positive numbers shift it right, negative left.
2px: Vertical offset of the effect. Positive numbers shift it down, negative up.
3px: The blur effect.  0 means no blur.
color: The color of the shadow.
*/