Extending Margins on WordPress CSS -

I am using a WordPress hosted site and my main concern is that I do not like them as margins Ho. I'm not sure how I can express it, but I give it a shot

This is the homepage with blog posts:

 < Code> blog title, blog body, here it is ... I just need to increase right margin   
 Again, it is not right that  too much  As it has been shown here - it has also been kept, I just want to expand the right margin, rather Which part of that code will be in it? Should I update it with the code?  
  Update   
 Is this code?  
 }. Entry Material {Overflow: Hidden; Zoom: 1; } / * Sidebar   
 or  
 } h3, #sidebar. Postdata, .entry-content {font-family: 'helvetica neue', helvetica, ariel, non-serif; }    
 
 
 without proper technical information (html and css code)). I'm guessing here that you should look for the  entry-content  class in your theme directory's .css file and add the desired margin.  
 If you can not find the square there, just add it at the end of the CSS file:  
  .entry-content {margin-right: 100px; }