Adding CSS to MyCustomCSS

Am I doing this correctly.

After installing My Custom CSS to my WordPress MU & network activating it across all sites, do I simply past new CSS code into the window & click save?

I added this code for eg:

.menu a {
color:#FFFFFF;
}

however, no change to the website. Do I need to add any additional description code into the window or modify any .php

PS. I am editing it as Super Admin

thanks

Mark

https://ww.wp.xz.cn/plugins/my-custom-css/