I'm getting a problem on my site because of layout difference between <div class="blog"> and <div class="item-page">. The page having <div class="blog"> display the content area where the text and articles get shown in my desired way i.e it is using the full width available to it but the page which has <div class="item-page"> do not uses the full width and some space is left between the article and the side menu. I want to remove that extra space. What should I do. If there is any other way instead of changing the class layout do let me know that too..

You can do this by change the class .item-page in the file templates/your_default_template_name/css/template.css and/or layout.css, position.css,... if have. You can copy the values from class .blog to class .item-page 

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