How to reduce the width of the blank fields in the sidebar and body?

1) You can reduce the sidebar margin with following css code:

.inner_sidebar {

margin-left: 50px;

}

Decrease the margin-left value. It’s not easily possible to change the outer margins or the margin between content area and sidebar because this will break the existing layouts and would require some major adjustments to the css grid.

2) Open up wp-contentthemesenfoldincludesloop-index.php and search for

$link = avia_image_by_id(get_post_thumbnail_id(), 'large', 'url');

You can replace “large” with any other thumbnail size (small, medium, portfolio, portfolio_small, entry_with_sidebar).