CSS field I used the following code
Hi. Are you talking about the CSS field inside the addon? When using this field, the addon's ID is automatically added to the selector that you use there. Therefore, at the output you get a code that will not work, like this (wrong selector).
#sppb-addon-1b7a2664-3a76-4b4c-afa5-472418e2c376 #sppb-addon-1b7a2664-3a76-4b4c-afa5-472418e2c376 {
border-width: 0 0 0 2px !important;
border-color: #e13505;
border-style: solid;
}
If you use addon's ID as selector, then the code should be added to Page CSS field or to Custom CSS Helix field or to custom.css file in Helix (the best option). Turn off Use Border option if you want to use CSS.
I would recommend that you do not use CSS Field inside an addon. In this field, you will not be able to edit the code for mobile devices and this increases the total amount of code, which harms performance.
And so it would be better
#sppb-addon-1b7a2664-3a76-4b4c-afa5-472418e2c376 {
border-left: 2px solid #e13505 !important;
}