1.栅格布局 12等分

.row{
  margin-left:-0.75rem;
  margin-right:-0.75rem;
}

.row::after{
  content:" ";
  display:block;
  clear:both;
}

[class*=column-*]{
  float:left;
  padding:0 0.75rem;
}

.column-1{ width:8.3333% };
.column-2{ width:16.6667% };
.column-3{ width:25% };
.column-4{ width:33.3333% };
.column-5{ width:41.6667% };
.column-6{ width:50% };
.column-7{ width:58.3333% };
.column-8{ width:66.6667% };
.column-9{ width:75% };
.column-10{ width:83.3333% };
.column-11{ width:91.667% };
.column-12{ width:100% };