absolute position horizontal center code example
Example 1: position absolute center
position: absolute;
margin-left: auto;
margin-right: auto;
left: 0;
right: 0;
Example 2: center absolute
#content {
position: absolute;
left: 0;
right: 0;
margin-left: auto;
margin-right: auto;
width: 100px; /* Need a specific value to work */
}