.contents-main .detail div.aligncenter {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

.contents-main .detail div.alignleft {
  float: left;
  margin: 0.5em 1em 0.5em 0;
}

.contents-main .detail div.alignright {
  float: right;
  margin: 0.5em 0 0.5em 1em;
}