It is good practice to create a child theme when you use WordPress.  If you are going to do some heavy CSS and custom work, then definately use a child theme.  It is pretty easy to set-up, and once it’s done you don’t need to worry about it anymore.  Follow these steps:

1. Create a new folder on your desktop called ‘divi-child’.
2. Use a text editor and made a new text file called ‘style.css’ and save it in the new divi-child folder.
3. Include the following text in the style.css file:

/*
Theme Name: Divi Child Theme
Theme URI: https://www.elegantthemes.com/gallery/divi/
Description: Divi Child Theme
Author: Elegant Themes
Author URI: https://www.elegantthemes.com
Template: Divi
Version: 1.0.0
*/

@import url(“../Divi/style.css”);

/* =Theme customization starts here
——————————————————- */

4. Zip the text file.
5. Upload this new zip file like a normal theme and activate.
6. Make any CSS changes in this text file.

If you are using Divi as described on the JFDI pages, you can use this ZIP file and upload: divi-child.zip

Read the below link for more information on making other style changes using the child theme.

Time: 10 minutes

Cost: None

Read: https://www.elegantthemes.com/blog/resources/wordpress-child-theme-tutorial