How can i keep the "add to cart" button text saying "added" once someone clicks on it?

Im using the add to cart button as a way for people to save my blog posts, here is a blog post where i have set the button up 

https://www.idmdiscovery.com/labels/analogical-force password: idm

i changed the add to cart text to save "favourite". when you click on the button it then says "added" but then it goes back to the original text with no indication to the user that its been clicked, i would like for it to stay saying "added" once someone clicks on it (adds to cart) or turn a different colour once its been clicked on, how would i go about doing this? thanks so much. 

Add the following to Design > Custom CSS.

#block-yui_3_17_2_1_1612857583760_17486 .cart-added .sqs-add-to-cart-button-inner {

  visibility : hidden !important;
  
  }

#block-yui_3_17_2_1_1612857583760_17486 .cart-added .sqs-add-to-cart-button-inner:before {

  content : 'Added';
  visibility : visible !important;
  
  }

Let us know how it goes.