Changing Image Size

Hey Spencer, saw a post elsewhere about adding the code to the .css to change image size but this doesn’t work for me.

.si_feed_widget .si_item {
width: 50%;
}

My images are in 2 columns at 65px; but I want them to be 85px . I tried changing ul#instagram li img but that’s not working.

Thanks in advanced!

https://wordpress.org/plugins/simple-instagram/