top

Values

<length> | <percentage> | <auto>

All positioned elements (elements that don't have position: static;)

Top defines the distance between the top of an element and the top of its surrounding block.

body .box{
position:fixed; top: 10px;
}
div#border{
position:absolute; top: 0;
}

Chrome	Firefox	Internet Explorer	Opera	Safari
1.0+	1.0+	5.0+	6.0+	1.0+