整个宽度分为24份，通过span属性来定义元素的宽度占多少
通过row组件提供的gutter属性来指定每一栏之间的间隔，默认间隔为0
通过col组件的offset属性来设置元素的偏移
通过flex布局来对分栏进行灵活的对齐并可通过 justify 属性来指定 start, center, end, space-between, space-around 其中的值来定义子元素的排版方式。
参考了bootstrap 响应式设计，预设了xs\sm\md\lg 4个尺寸
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<!-- import CSS -->
<link rel="stylesheet" href="https://unpkg.com/element-ui/lib/theme-chalk/index.css">
<script src="https://unpkg.com/vue/dist/vue.js"></script>
<script src="https://unpkg.com/element-ui/lib/index.js"></script>
</head>
<body>
<div id="app">
<el-row>
<el-col :span="24"><div class="grid-content bg-purple-dark"></div></el-col>
</el-row>
<el-row>
<el-col :span="12"><div class="grid-content bg-purple"></div></el-col>
<el-col :span="12"><div class="grid-content bg-purple-light"></div></el-col>
</el-row>
<el-row>
<el-col :span="8"><div class="grid-content bg-purple"></div></el-col>
<el-col :span="8"><div class="grid-content bg-purple-light"></div></el-col>
<el-col :span="8"><div class="grid-content bg-purple"></div></el-col>
</el-row>
<el-row>
<el-col :span="6"><div class="grid-content bg-purple"></div></el-col>
<el-col :span="6"><div class="grid-content bg-purple-light"></div></el-col>
<el-col :span="6"><div class="grid-content bg-purple"></div></el-col>
<el-col :span="6"><div class="grid-content bg-purple-light"></div></el-col>
</el-row>
<el-row>
<el-col :span="4"><div class="grid-content bg-purple"></div></el-col>
<el-col :span="4"><div class="grid-content bg-purple-light"></div></el-col>
<el-col :span="4"><div class="grid-content bg-purple"></div></el-col>
<el-col :span="4"><div class="grid-content bg-purple-light"></div></el-col>
<el-col :span="4"><div class="grid-content bg-purple"></div></el-col>
<el-col :span="4"><div class="grid-content bg-purple-light"></div></el-col>
</el-row>
</div>
<style>
.el-row {
margin-bottom: 20px;
&:last-child {
margin-bottom: 0;
}
}
.el-col {
border-radius: 4px;
}
.bg-purple-dark {
background: #99a9bf;
}
.bg-purple {
background: #d3dce6;
}
.bg-purple-light {
background: #e5e9f2;
}
.grid-content {
border-radius: 4px;
min-height: 36px;
}
.row-bg {
padding: 10px 0;
background-color: #f9fafc;
}
</style>
</body>
<script>
new Vue({
el: '#app',
data: function() {
return { visible: false }
}
})
</script>
</html>