img { margin-left: auto;   margin-right: auto; border-style:solid; border-color:white; border-width:3px;}
img.num { margin-left: auto;   margin-right: auto; border-style:solid; border-color:white; border-width:0px;}
body { text-align: center; background-color:green; color:white; font-family:arial; margin-top:50px}