css3: translateX to center element horizontally

Question

I\'m trying to center horizontally an element: jsfiddle

On the child I

Answer 1

You were missing a position relative on your parent, position absolute on the child and the left and top values to help offset the child.

DEMO http://jsfiddle.net/nA355/6/

#parent {
    width: 300px;
    height: 100px;
    background-color: black;
    border: 1px solid grey;
    position: relative;
}
#child {
    position: absolute;
    height: 100px;
    width: 20px;
    left: 50%;
    top: 50%;
    -webkit-transform: translateX(-50%) translateY(-50%);
    -moz-transform: translateX(-50%) translateY(-50%);
    transform: translateX(-50%) translateY(-50%);
    background-color:red;
}