Overriding the color on back button

Hi all,

First off – thank you for creating this widget! Very helpful.

Was wondering how to edit the color on your button. I’m using Elementor, and I’ve tried changing it in the Custom CSS page, and in the actual shortcode widget but can’t change it from black.

Could you tell me where in WordPress I should change it in? And am I using the CSS code

This is what I am using:
.alg_back_button {
background: #fbfbf8 !important;
}