/* 容器方向 */
.flex {
  display: flex;
}
.flex-row {
  flex-direction: row;
}
.flex-col {
  flex-direction: column;
}

/* 主轴对齐 */
.justify-start {
  justify-content: flex-start;
}
.justify-center {
  justify-content: center;
}
.justify-end {
  justify-content: flex-end;
}
.justify-between {
  justify-content: space-between;
}
.justify-around {
  justify-content: space-around;
}
.justify-evenly {
  justify-content: space-evenly;
}

/* 交叉轴对齐 */
.items-start {
  align-items: flex-start;
}
.items-center {
  align-items: center;
}
.items-end {
  align-items: flex-end;
}
.items-stretch {
  align-items: stretch;
}

/* 多行交叉轴对齐 */
.content-start {
  align-content: flex-start;
}
.content-center {
  align-content: center;
}
.content-end {
  align-content: flex-end;
}
.content-between {
  align-content: space-between;
}
.content-around {
  align-content: space-around;
}
.content-stretch {
  align-content: stretch;
}

/* 子项扩展 */
.flex-1 {
  flex: 1 1 0%;
}
.flex-auto {
  flex: 1 1 auto;
}
.flex-none {
  flex: none;
}

/* 换行控制 */
.flex-wrap {
  flex-wrap: wrap;
}
.flex-nowrap {
  flex-wrap: nowrap;
}
.flex-wrap-reverse {
  flex-wrap: wrap-reverse;
}

/* 对齐自身 */
.self-start {
  align-self: flex-start;
}
.self-center {
  align-self: center;
}
.self-end {
  align-self: flex-end;
}