Fix sentence in css.html

css.html

@@ -1775,7 +1775,7 @@ For example, <code>&lt;section&gt;</code> should be wrapped as inline.
 {% endhighlight %}
 
     <h4>Inline checkboxes</h4>
-    <p>Use <code>.checkbox-inline</code> or <code>.radio-inline</code> class to a series of checkboxes or radios for controls that appear on the same line.</p>
+    <p>Use the <code>.checkbox-inline</code> or <code>.radio-inline</code> classes on a series of checkboxes or radios for controls that appear on the same line.</p>
     <div class="bs-example">
       <form role="form">
         <label class="checkbox-inline">