A full-width row spans the entire width of the page from edge to edge.
If you use a third party theme, you may need to add some additional CSS to get your rows to be full width. Here's something you can try.
First, find the ID or class name of your theme’s content wrapper. If you look
at the HTML source for a page, the content wrapper is usually a
that occurs after the header block, and it often uses an ID or class with the
content, for example:
Next, write a rule for the class
fl-builder with that content wrapper ID or
class inside it. If
id="content" is the selector for your content wrapper,
then the rule would look like this:
See the article on where to put custom CSS code.
If you cannot get this rule to work, please contact Support for help.