#idea1 {background:url(/idea_image_resize/9/291) no-repeat; margin-right:5px;}
#idea2 {background:url(/idea_image_resize/11/291) no-repeat;}

<!-- #idea3 {background:url() no-repeat; margin-right:0px;}
#idea4 {background:url() no-repeat;} -->

#idea3 {background:url(/idea_image_resize/12/291) no-repeat;}

#idea4 {background:url(/idea_image_resize/13/291) no-repeat;}