flex布局，每行放三个，分散对齐
.***modityBox{//父容器
display: flex;
flex-wrap: wrap;
}
.box{//子容器
width: 32%;
height: 150px;
border-radius: 4px;
border: 1px solid #***c;
margin-bottom: 20px;
}
.box:not(:nth-child(3n)) {
margin-right: calc(6% / 3);
}
