#list {
      position: relative;
      max-width: 900px;
      margin: 0 auto;   /*全体の中央寄せ*/
    }
    #container {
      width: 100%;
      margin: 0 auto;   /*中央寄せ*/
      position: relative;
    }
    .item {
      margin: 2px;
      width: 165px;
      padding: 0px;
      border: 1px solid #eee;
      float: left;   /*Lazy Load */
    }
    .item.x2 {
      width: 345px;
    }
    .item.x3 {
      width: 525px;
    }
    .item img {
      width: 100%;
    }

@media screen and (max-width: 600px) {
.item.x3 {
	width: 300px;
}
}

@media screen and (max-width: 480px) {
.item {
	margin: 5px auto;
	width: 140px;
	padding: 4px;
	border: 1px solid #eee;
	float: none;   /*Lazy Load */
}
.item.x2 {
	/*max-width: 480px;*/
	width: 300px;
}
.item.x3 {
	width: 300px;
}
}