page {
    font-family: -apple-system-font,Helvetica Neue, Helvetica,微软雅黑,"Microsoft YaHei",  sans-serif;
    /* 宽高包括边框 */
    box-sizing:border-box;
}
/* 水平居中 */
.horizontal{
  display: flex;
  align-items: center;
}
/* 平均分布 */
.between{
  display: flex;
  justify-content: space-between;
}