Grid systems are used for creating page layouts through a series of rows and columns that house your content.

The ACS-Bootstrap grid system is based off of the Twitter Bootstrap, which utilizes 12 columns, making for a 940px wide container without responsive features enabled. With the responsive CSS file added, the grid adapts to be 767px and 1200px wide depending on your viewport. Below 767px viewports, the columns become fluid and stack vertically.

How the grid system works

  • Rows must be placed within a .container (fixed-width) or .container-fluid (full-width) for proper alignment and padding.
  • Use rows to create horizontal groups of columns.
  • Content should be placed within columns, and only columns may be immediate children of rows.
  • Columns create gutters (gaps between column content) via padding. That padding is offset in rows for the first and last column via negative margin on .rows.
  • The negative margin is why the examples below are outdented. It's so that content within grid columns is lined up with non-grid content.
  • Grid columns are created by specifying the number of twelve available columns you wish to span. For example, three equal columns would use three .col-xs-4.
  • If more than 12 columns are placed within a single row, each group of extra columns will, as one unit, wrap onto a new line.
  • Grid classes apply to devices with screen widths greater than or equal to the breakpoint sizes, and override grid classes targeted at smaller devices. Therefore, e.g. applying any .col-md-* class to an element will not only affect its styling on medium devices but also on large devices if a .col-lg-* class is not present.
<div class="container">
<div class="row">
  <div class="col-md-8">...</div>
  <div class="col-md-4">...</div>
</div>
</div>

Grid Options

 Extra small devices Phones (<768px)Small devices Tablets (≥768px)Medium devices Desktops (≥992px)Large devices Desktops (≥1200px)
Grid behaviorHorizontal at all timesCollapsed to start, horizontal above breakpoints
Container widthNone (auto)750px970px1170px
Class prefix.col-xs-.col-sm-.col-md-.col-lg-
# of columns12
Column widthAuto~62px~81px~97px
Gutter width30px (15px on each side of a column)
NestableYes
OffsetsYes
Column orderingYes

Example: Stacked-to-horizontal

1
1
1
1
1
1
1
1
1
1
1
1
4
4
4
6
6
12
<div class="row">
   <div class="col-md-1">...</div>
   <div class="col-md-1">...</div>
   <div class="col-md-1">...</div>
   <div class="col-md-1">...</div>
   <div class="col-md-1">...</div>
   <div class="col-md-1">...</div>
   <div class="col-md-1">...</div>
   <div class="col-md-1">...</div>  
   <div class="col-md-1">...</div>
   <div class="col-md-1">...</div>
   <div class="col-md-1">...</div>
   <div class="col-md-1">...</div>      
</div>
<div class="row">
   <div class="col-md-4">...</div>
   <div class="col-md-4">...</div>
   <div class="col-md-4">...</div>
</div>
<div class="row">    
   <div class="col-md-6">...</div>
   <div class="col-md-6">...</div>
</div>
<div class="row">    
   <div class="col-md-12">...</div>     
</div>

Example: Fluid container

Turn any fixed-width grid layout into a full-width layout by changing your outermost .container to .container-fluid.

<div class="container-fluid">
  <div class="row">
    ...
  </div>
</div>

 

Example: Mobile and desktop

Don't want your columns to simply stack in smaller devices? Use the extra small and medium device grid classes by adding .col-xs-* .col-md-* to your columns. See the example below for a better idea of how it all works.

.col-xs-12 .col-md-8
.col-xs-6 .col-md-4
.col-xs-6 .col-md-4
.col-xs-6 .col-md-4
.col-xs-6 .col-md-4
.col-xs-6
.col-xs-6
<!-- Stack the columns on mobile by making one full-width and the other half-width -->
<div class="row">
  <div class="col-xs-12 col-md-8">.col-xs-12 .col-md-8</div>
  <div class="col-xs-6 col-md-4">.col-xs-6 .col-md-4</div>
</div>

<!-- Columns start at 50% wide on mobile and bump up to 33.3% wide on desktop -->
<div class="row">
  <div class="col-xs-6 col-md-4">.col-xs-6 .col-md-4</div>
  <div class="col-xs-6 col-md-4">.col-xs-6 .col-md-4</div>
  <div class="col-xs-6 col-md-4">.col-xs-6 .col-md-4</div>
</div>

<!-- Columns are always 50% wide, on mobile and desktop -->
<div class="row">
  <div class="col-xs-6">.col-xs-6</div>
  <div class="col-xs-6">.col-xs-6</div>
</div>

 

Example: Mobile, tablet, desktop

Build on the previous example by creating even more dynamic and powerful layouts with tablet .col-sm-* classes.

.col-xs-12 .col-sm-6 .col-md-8
.col-xs-6 .col-md-4
.col-xs-6 .col-sm-4
.col-xs-6 .col-sm-4
 
.col-xs-6 .col-sm-4
<div class="row">
  <div class="col-xs-12 col-sm-6 col-md-8">.col-xs-12 .col-sm-6 .col-md-8</div>
  <div class="col-xs-6 col-md-4">.col-xs-6 .col-md-4</div>
</div>
<div class="row">
  <div class="col-xs-6 col-sm-4">.col-xs-6 .col-sm-4</div>
  <div class="col-xs-6 col-sm-4">.col-xs-6 .col-sm-4</div>
  <!-- Optional: clear the XS cols if their content doesn't match in height -->
  <div class="clearfix visible-xs-block"></div>
  <div class="col-xs-6 col-sm-4">.col-xs-6 .col-sm-4</div>
</div>

 

Offsetting columns

Move columns to the right using .col-md-offset-* classes. These classes increase the left margin of a column by * columns. For example, .col-md-offset-4 moves .col-md-4 over four columns.

.col-md-4
.col-md-4 .col-md-offset-4
.col-md-3 .col-md-offset-3
.col-md-3 .col-md-offset-3
.col-md-6 .col-md-offset-3
<div class="row">
  <div class="col-md-4">.col-md-4</div>
  <div class="col-md-4 col-md-offset-4">.col-md-4 .col-md-offset-4</div>
</div>
<div class="row">
  <div class="col-md-3 col-md-offset-3">.col-md-3 .col-md-offset-3</div>
  <div class="col-md-3 col-md-offset-3">.col-md-3 .col-md-offset-3</div>
</div>
<div class="row">
  <div class="col-md-6 col-md-offset-3">.col-md-6 .col-md-offset-3</div>
</div>

 

Nesting columns

To nest your content with the default grid, add a new .row and set of .col-sm-* columns within an existing .col-sm-* column. Nested rows should include a set of columns that add up to 12 or fewer (it is not required that you use all 12 available columns).

Level 1: .col-sm-9
Level 2: .col-xs-8 .col-sm-6
Level 2: .col-xs-4 .col-sm-6
<div class="row">
  <div class="col-sm-9"> Level 1: .col-sm-9 
    <div class="row">
      <div class="col-xs-8 col-sm-6"> Level 2: .col-xs-8 .col-sm-6 </div> 
      <div class="col-xs-4 col-sm-6"> Level 2: .col-xs-4 .col-sm-6 </div> 
    </div> 
  </div>
</div>

 

Column ordering

Easily change the order of our built-in grid columns with .col-md-push-* and .col-md-pull-* modifier classes.

.col-md-9 .col-md-push-3
.col-md-3 .col-md-pull-9
<div class="row">
   <div class="col-md-9 col-md-push-3">.col-md-9 .col-md-push-3</div>
   <div class="col-md-3 col-md-pull-9">.col-md-3 .col-md-pull-9</div>
</div>