.flex {
    display: flex;
}
.row {
    flex-direction: row;
}
.column {
    flex-direction: column;
}
/* 主轴对齐方式 */
.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;
}

/* 交叉轴对齐方式 */
.items-start {
    align-items: flex-start;
}

.items-center {
    align-items: center;
}

.items-end {
    align-items: flex-end;
}

.items-stretch {
    align-items: stretch;
}

.items-baseline {
    align-items: baseline;
}