You can paste the following code on the custom CSS box of your Design tab:
div[class^='form-components-style_single-step-content'] {background-color: rgba(0,0,0,.25);}
You can paste the following code on the custom CSS box of your Design tab:
div[class^='form-components-style_single-step-content'] {background-color: rgba(0,0,0,.25);}