一行文字居中，两行或多行文字同样居中

HTML

<div class="book-detail-store-item align-center-vertical">居中文字</div>

CSS

.book-detail-store-item {width: 50px；height：50px；line-height: 25px;font-size: 12px;}/*flex垂直居中对齐*/
.align-center-vertical{display: flex;align-items: center;justify-content: space-around;flex-direction: column;
}