Check out your CSS with your browser’s “Inspector” element to find the constraint. Generally, right-clicking on any page content of interest will give you a menu including the “Inspect Element” option. For example, in Google Chrome: https://developers.google.com/web/tools/chrome-devtools/iterate/inspect-styles/edit-styles
See also: Reviews are reformatted to unacceptable short line length - #5 by wfb