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                <h3>初期値:top left</h3>
<div class="background repeat"></div>
<div class="background center"></div>
<div class="background right"></div>
<div class="background left"></div>
<h3>上側中央寄せ:top center</h3>
<div class="background top-center"></div>
<h3>右上寄せ:top right</h3>
<div class="background top-right"></div>
<h3>下側中央寄せ:bottom center</h3>
<div class="background bottom-center"></div>
<h3>左下寄せ:left bottom</h3>
<div class="background left-bottom"></div>
<h3>右下寄せ:right bottom</h3>
<div class="background right-bottom"></div>


                .background {
  margin-bottom: 10px;
  width: 300px;
  height: 120px;
  background-color: yellow;
  background-image: url("");
  background-repeat: no-repeat;
  background-size: 100px;
} {
  background-position: center;

.background.right {
  background-position: right;

.background.left {
  background-position: left;
} {
  background-position: top center;
} {
  background-position: top right;

.background.bottom-center {
  background-position: bottom center;

.background.left-bottom {
  background-position: left bottom;

.background.right-bottom {
  background-position: right bottom;