Once you click on the “Edit Template” the Template Editor will open. (See Below Screenshot). In the Template Editor, there are 3 sections. 1. Files 2. Modified File 3. Original File. Under Files, you can see the “+” symbol. Click on the “+” to expand the file list. Here you can see different types of file categories including, CSS, HTML, Fonts, js, Images etc.
There two types of files, one which you can edit and the one which is not editable. The files which are editable are hyperlinked. When you click on these files it will open in “Modified File” section. Here you can make the necessary changes to the file and then click on “Save”. If you have made any changes to a file by mistake, then click on the “Original File” and compare it with the “Modified File” to know what changes you have made. If you want to revert the changes you have made, then simply copy the original file and paste it in the modified file section and click on "Save'.
Note: You cannot make any changes to the Original File. You can make changes to any single HTML or CSS file through Template Editor. After making necessary changes just click on “Save”.