Merge pull request #10423 from hustlzp/master

CSS docs - Grid section: two dots are missing before 'col-md-8'

css.html

@@ -239,7 +239,7 @@ base_url: "../"
     <p>Don't want your columns to simply stack in smaller devices? Use the extra small and medium device grid classes by adding <code>.col-xs-*</code> <code>.col-md-*</code> to your columns. See the example below for a better idea of how it all works.</p>
     <div class="bs-docs-grid">
       <div class="row show-grid">
-        <div class="col-xs-12 col-md-8">.col-xs-12 col-md-8</div>
+        <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>
       <div class="row show-grid">
@@ -255,7 +255,7 @@ base_url: "../"
 {% highlight html %}
 <!-- 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-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>