将有关的源码文件复制一份，然后写demo；进行编译：

@import "grid.less";
@import "variables.less";
@import "less里面的mixins--即混合/grid.less";
@import "less里面的mixins--即混合/clearfix.less";
@import "less里面的mixins--即混合/grid-framework.less";

首先将grid-framework.less里面的col-改成自己命名的

.clearfix：更改 加括号没有继承

.clearfix {
  &:before,
  &:after {
    display: table; // 2
    content: " "; // 1
  }
  &:after {
    clear: both;
  }
}