title: how to change font size of word document using .net
body: <p>I am working on a application using C# and Spire.Doc which saves the word document to specified format which includes logo at the header and specified font size and style.</p>
  
  <p>Now I can paste logo at the header using spire.doc but I'm not able to change the <strong>font</strong> style and <strong>size</strong> of the whole document:</p>
  
  <pre><code>font size should be 10;
  font should be: franklin gothic demi
  </code></pre>
  
  <p>Can someone please help me for this?
  Thanks in advance.</p>