title: rotate menu slide from right to left
body: <p>how to rotate collapse menu slide from right to left?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="false" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;HTML&gt;
  
  &lt;HEAD&gt;
    &lt;style&gt;
      #accordion {
        width: 55%;
        margin-left: 20px;
        border: 1px solid blue;
      }
      .panel {
        width: 100%;
      }
      .panel-heading {
        height: 40px;
      }
      .panel-title {
        height: 18px
      }
      .panel-title a {
        float: right;
        text-decoration: none;
        padding: 0px 10px;
        margin: 0px -10px;
      }
      .panel-body {
        height: 10%;
      }
      .cont {
        margin: 10px 00px;
      }
    &lt;/style&gt;
    &lt;META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"&gt;
    &lt;meta name="viewport" content="width=device-width, initial-scale=1"&gt;
    &lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"&gt;&lt;/script&gt;
    &lt;script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"&gt;&lt;/script&gt;
    &lt;link href="http://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css" rel="stylesheet" /&gt;
    &lt;TITLE&gt;headerFrame.jsp&lt;/TITLE&gt;
  
  &lt;/HEAD&gt;
  
  &lt;BODY&gt;
  &lt;br&gt;
    &lt;div&gt;
      &lt;div class="panel-group" id="accordion"&gt;
        &lt;div class="panel panel-default"&gt;
          &lt;div class="panel-heading"&gt;
            &lt;h4 class="panel-title"&gt;
          &lt;a data-toggle="collapse" data-parent="#accordion" href="#collapseOne"&gt;
            Collapsible Group Item #1
          &lt;/a&gt;
        &lt;/h4&gt;
  
          &lt;/div&gt;
          &lt;div id="collapseOne" class="panel-collapse collapse in"&gt;
            &lt;div class="panel-body"&gt;
              &lt;div class="cont"&gt;testing msesage&lt;/div&gt;
            &lt;/div&gt;
          &lt;/div&gt;
        &lt;/div&gt;
  
  
      &lt;/div&gt;
    &lt;/div&gt;
  &lt;/BODY&gt;
  
  &lt;/HTML&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <h2>expected</h2>
  
  <p><a href="https://i.stack.imgur.com/cIrgA.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cIrgA.png" alt="enter image description here"></a></p>