Affiliate disclaimer - Background

I have added the affiliate disclaimer alignment to the site for each posts.

Right now i am getting only the one with white background. Tried adding the below code to the Additional CSS in the homepage but getting error message "Markup is not allowed in CSS" can you please let me know how to add it properly.

.affiliatedisclaimer {<br> color: #3c763d;<br> background-color: #dff0d8;<br> border: #cae6be 2px solid;<br> padding: 20px 10px 0px 20px;<br> margin-bottom: 40px;}

https://imgur.com/a/gVbYw9y