title: How to use span and offset class in twitter bootstrap
body: <p>I am just a beginner in Twitter Bootstrap.</p>
  
  <p>I am trying to use its grid functionality by using classes span and offset.</p>
  
  <p>Here is my code:</p>
  
  <pre><code> &lt;!DOCTYPE html&gt;
  &lt;html&gt;
    &lt;head&gt;
      &lt;title&gt;Bootstrap 101 Template&lt;/title&gt;
      &lt;meta name="viewport" content="width=device-width, initial-scale=1.0"&gt;
  &lt;style&gt;
  
  ul.unstyled &gt; li {
    list-style-type: none;
  }
  &lt;/style&gt; 
   &lt;/head&gt;
  
  &lt;body&gt;
  &lt;script src="http://code.jquery.com/jquery.js"&gt;&lt;/script&gt;
      &lt;script src="bootstrap/js/bootstrap.min.js"&gt;&lt;/script&gt;
  &lt;div class="row"&gt;
  &lt;div class="span3 offset5"&gt;
  &lt;ul class="unstyled"&gt;
  &lt;li&gt;
  &lt;label for="optionsRadios1"&gt;A.&lt;/label&gt;
  &lt;input type="radio" name="optionsRadios" id="optionsRadios1" value="option1" checked&gt;Option 1
  &lt;/li&gt;
  &lt;li&gt;
  &lt;label for="optionsRadios2"&gt;B.&lt;/label&gt;
    &lt;input type="radio" name="optionsRadios" id="optionsRadios2" value="option2"&gt;Option 2 
  &lt;/li&gt;
  &lt;li&gt;
  &lt;label for="optionsRadios3"&gt;C.&lt;/label&gt;
  &lt;input type="radio" name="optionsRadios" id="optionsRadios3" value="option3"&gt;option3&lt;/li&gt;
  &lt;li&gt;&lt;label for="optionsRadios4"&gt;D.&lt;/label&gt;
  &lt;input type="radio" name="optionsRadios" id="optionsRadios4" value="option4"&gt;option4&lt;/li&gt;
  
  &lt;li&gt;&lt;label for="optionsRadios5"&gt;E.&lt;/label&gt;
  &lt;input type="radio" name="optionsRadios" id="optionsRadios5" value="option5"&gt;option5&lt;/li&gt;
  
  &lt;/ul&gt;
  &lt;/div&gt;
  &lt;/div&gt;
  &lt;div class="row"&gt;
  &lt;div class="span3 offset5"&gt;
  &lt;input type="checkbox"&gt;Mark To review&lt;/input&gt;
  &lt;/div&gt;
  &lt;/div&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Can anyone please tell me where I am mistaking?
  I am not getting offset margin in my webpage.</p>
  
  <p><img src="https://i.stack.imgur.com/YUVX6.png" alt="enter image description here"></p>
  
  <p>I used code described in Bootstrap example <a href="http://twitter.github.io/bootstrap/scaffolding.html#gridSystem" rel="noreferrer">http://twitter.github.io/bootstrap/scaffolding.html#gridSystem</a>
  My HTML webpage code is </p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
    &lt;head&gt;
      &lt;title&gt;Bootstrap 101 Template&lt;/title&gt;
      &lt;meta name="viewport" content="width=device-width, initial-scale=1.0"&gt;
   &lt;/head&gt;
  
  &lt;body&gt;
  &lt;script src="http://code.jquery.com/jquery.js"&gt;&lt;/script&gt;
      &lt;script src="bootstrap/js/bootstrap.min.js"&gt;&lt;/script&gt;
  &lt;div class="row"&gt;
  &lt;div class="span9"&gt;
      Level 1 column
      &lt;div class="row"&gt;
        &lt;div class="span6"&gt;Level 2&lt;/div&gt;
        &lt;div class="span3"&gt;Level 2&lt;/div&gt;
  &lt;/div&gt;
  &lt;/div&gt;
  
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>And I am not getting my page with no margins or offsets. Here's the screenshot:
  <img src="https://i.stack.imgur.com/AU6UW.png" alt="enter image description here"> I am unable to point where the problem is. </p>