table.sortable th::after{position:relative;width:20px;height:20px;background-image:url("./sort_both.png");background-size:contain;background-position:center;background-repeat:no-repeat;content:'　'}table.sortable th.dir-u::after{background-image:url("./sort_asc.png")}table.sortable th.dir-d::after{background-image:url("./sort_desc.png")}table.sortable th.no-sort::after{background:none}