.mark_entry {
    position: relative;
    width: 13px;
}

.mark_entry .mark_entry_icon {
    background: url("images/checked.png") no-repeat 0 0;
    background-size: 13px;
    width: 13px;
    height: 13px;
    display: none;
}

.mark_entry_show .mark_entry_icon {
    display: inline-block;
}