The default grid system provided in Bootstrap utilizes 12 columns that render out at widths of 724px, 940px (default without responsive CSS included), and 1170px. Below 767px viewports, the columns become fluid and stack vertically.
<div class="row">
<div class="span4">...</div>
<div class="span8">...</div>
</div>
As shown here, a basic layout can be created with two "columns", each spanning a number of the 12 foundational columns we defined as part of our grid system.
<div class="row">
<div class="span4">...</div>
<div class="span4 offset4">...</div>
</div>
With the static (non-fluid) grid system in Bootstrap, nesting is easy. To nest your content, just add a new .row and set of .span* columns within an existing .span* column.
.span3 columns should be placed within a .span6.
<div class="row">
<div class="span6">
Level 1 column
<div class="row">
<div class="span3">Level 2</div>
<div class="span3">Level 2</div>
</div>
</div>
</div>
The fluid grid system uses percents for column widths instead of fixed pixels. It also has the same responsive variations as our fixed grid system, ensuring proper proportions for key screen resolutions and devices.
确实，互联网让知识来得那么容易，知之为知之很方便，很多人都以为知之等于学会，知之越多，学会越多，于是碎片化学习大行其道。这时，还是实习生的Joe做出一个大胆举动，他说服公司聘用他的一些朋友加盟，大家组成团队共同为公司解决技术难题。
<div class="row-fluid">
<div class="span4">...</div>
<div class="span8">...</div>
</div>
Nesting with fluid grids is a bit different: the number of nested columns doesn't need to match the parent. Instead, your columns are reset at each level because each row takes up 100% of the parent column.
<div class="row-fluid">
<div class="span12">
Level 1 of column
<div class="row-fluid">
<div class="span6">Level 2</div>
<div class="span6">Level 2</div>
</div>
</div>
</div>
The default and simple 940px-wide, centered layout for just about any website or page provided by a single <div class="container">.
<body>
<div class="container">
...
</div>
</body>
<div class="container-fluid"> gives flexible page structure, min- and max-widths, and a left-hand sidebar. It's great for apps and docs.
<div class="container-fluid">
<div class="row-fluid">
<div class="span2">
<!--Sidebar content-->
</div>
<div class="span10">
<!--Body content-->
</div>
</div>
</div>
Media queries allow for custom CSS based on a number of conditions—ratios, widths, display type, etc—but usually focuses around min-width and max-width.
告知用户当前状态 用户在任何时候都希望能够了解当前所处的状态，而不用过多猜测。并且一着不慎，甚至连从头来过的机会都没有。
比如我想给产品拍个介绍视频放在淘宝店里啦，我想给企业家做个访谈视频放在官网上啦。华商韬略(微信公众号：hstl8888)总结如下： 黑牛食品是一家A股上市公司，主要生产豆奶、麦片、核桃粉等产品，从2012年开始，其业绩由于产品市场饱和持续下滑，管理层迫切需要一个能快速扭转局面的产品，于是相中了爆发中的预调鸡尾酒
| Label | Layout width | Column width | Gutter width |
|---|---|---|---|
| Smartphones | 480px and below | Fluid columns, no fixed widths | |
| Smartphones to tablets | 767px and below | Fluid columns, no fixed widths | |
| Portrait tablets | 768px and above | 42px | 20px |
| Default | 980px and up | 60px | 20px |
| Large display | 1200px and up | 70px | 30px |
但从百度这样的公司出去，让毕胜感到高不成低不就，大公司他不愿意受人家的制度与文化约束，“我在百度期间，李彦宏都比较少管我。
<meta name="viewport" content="width=device-width, initial-scale=1.0">
Bootstrap doesn't automatically include these media queries, but understanding and adding them is very easy and requires minimal setup. You have a few options for including the responsive features of Bootstrap:
Why not just include it? Truth be told, not everything needs to be responsive. Instead of encouraging developers to remove this feature, we figure it best to enable it.
/* Landscape phones and down */
@media (max-width: 480px) { ... }
/* Landscape phone to portrait tablet */
@media (max-width: 767px) { ... }
/* Portrait tablet to landscape and desktop */
@media (min-width: 768px) and (max-width: 979px) { ... }
/* Large desktop */
@media (min-width: 1200px) { ... }
For faster mobile-friendly development, use these basic utility classes for showing and hiding content by device.
”古井贡投资3000万元打造的佰色预调酒则只在生产地安徽销售，而且没有做起来。”柳传志也说：“做正确的事，比把事做正确更重要。
一个创业者可以是CEO、CTO、CFO、COO，甚至可以出任CWO(首席微信运营官)，从采购、财务、人事、产品到运营乃至行政保洁卫生，创业者都可以一肩挑。“对于优酷这种大的平台，通过阿里巴巴消费数据的挖掘，能够挖掘出更成规模的变现方法，这确实是我们当时重要考量的地方。
其次，巨额的运营费用也让友友用车的前行倍感吃力。但是换个角度，从在社会事件中对错误舆论进行正向引导、斧正的角色来看，知乎平台也具备其他平台力所不及的能力。
| Class | Phones 480px and below | Tablets 767px and below | Desktops 768px and above |
|---|---|---|---|
.visible-phone |
Visible | Hidden | Hidden |
.visible-tablet |
Hidden | Visible | Hidden |
.visible-desktop |
Hidden | Hidden | Visible |
.hidden-phone |
Hidden | Visible | Visible |
.hidden-tablet |
Visible | Hidden | Visible |
.hidden-desktop |
Visible | Visible | Hidden |