# 网格系统

## Grid

## props

+ `fixed` the fixed grid has a `max-width: 1000px;` limit
+ `collapse` a grid with collapse has no padding

## Column

## props

+ `sm` am-u-sm-* class, 1~12
+ `md` am-u-md-* class, 1~12
+ `lg` am-u-lg-* class, 1~12
+ `end` am-u-end class, Boolean
+ `centered` am-u-*-centered class, sm|md|lg

## container