How to center multiple layers in a layer without changing the layout_html/css_WEB-ITnose

As the title says, I write a layer in an html and then write a large number of layers in it. How to center those layers without changing the layout?
The following are the styles of some layers

#mindb{
background-image:url(images/main_29.gif);
width:8px;
height:29px ;
position:absolute;
left:89px;
top:480px;
}
#mindc{
background-image:url(images/main_30.gif);
width:247px;
height:29px;
position:absolute;
left:97px;
top:480px;
}
#mindd{
background-image: url(images/main_32.gif);
width:11px;
height:29px;
position:absolute;
left:344px;
top:480px;
}

Reply to the discussion (solution)

Well... ok I already know...

Congratulations on your progress again

It’s good to solve it yourself