title: Find and add missing style attributes to an html string in C#
body: <p>I am stuck in a tricky situation, I have this string in C# with html tags :</p>
  
  <p>string strHTML = "<code>&lt;span style="font-size: 10px;"&gt;Hi This is just a section of html text.&lt;/span&gt;&lt;span style="font-family: 'Verdana'; font-size: 10px;"&gt;Please help&lt;/span&gt;&lt;span&gt;me add style attributes to span tags.Thank You&lt;/span&gt;</code>";</p>
  
  <p>As you can see, there are two span tags without "font-family: 'Verdana';". I need something that can help me add font-family to those two span tags so the desired result would be something like this:</p>
  
  <p>"<code>&lt;span style="font-size: 10px;font-family: 'Verdana';"&gt;Hi This is just an example of html text.&lt;/span&gt;&lt;span style="font-family: 'Verdana'; font-size: 10px;"&gt;Please help&lt;span style="font-family: 'Verdana';"&gt;me add style attributes to span tags.Thank You&lt;/span&gt;</code>"</p>
  
  <p>I know that I can simply add another span tag at the beginning of the string but that is something I don't want to do. 
  Any help would be much appreciated.</p>
  
  <p>Edits: I tried using Regex.Replace method for hours. But I just could not get the correct output.</p>