title: change button font size in Extjs 4
body: <p>do the following change for css but not able to change font size  </p>
  
  <pre><code>set style 
  
  font-size: 16px;
  
  and also set css class 
  
  .x-btn{
   font:normal 18px tahoma, verdana, helvetica;
  }
  
  .x-btn button{
      font:normal 18px arial,tahoma,verdana,helvetica;
      color:#333;
  }
  
  .x-btn em {
      font-style:normal;
      font-weight:normal;
  }
  </code></pre>
  
  <p>help me to change font size in Extjs Button</p>