Footer right aligned text not centering on mobile

I have tried all of the custom code written for centering footer text on mobile only and none of it seems to work. Please help!

I want to keep the text right aligned on desktop but have it center on mobile and tablet. I currently have this code which is not working:

@media screen and (max-width:900px) {
div#yui_3_17_2_1_1574529725307_707 * {
    text-align: center;
}
}

https://sepia-cardioid-z8gf.squarespace.com   Pass: acupuncture

add to custom css

@media screen and (max-width:900px) {
div#block-yui_3_17_2_1_1567277763748_131526 * {
    text-align: center !important;
}
}

DON'T USE #YUI, it will change every you reload the page.

Use #page-id or #block-yui

Amazing! It worked perfectly. I can't seem to locate the block yui id in the inspected code. How would I do the same for the copyright line? 

Nevermind - found it 🙂

Thank you so much! @tuanphan