How to center a text block on mobile only

Hi, 

I'm looking for a CSS code to change alignment on text block in mobile ONLY. 

Preferably center, but also would love the codes for left / right. 

Need it on a lot of blocks but as an example: 

homepage text block on mobile: 

#block-ed20e2002a61eaf311bb

password: smoothie123

I tried this CSS but it is not working:

@media screen and (max-width:767px) {

#enter-block-id-here>div {

text-align: center !important;

}

}

5 minutes ago, Manouk said:

@media screen and (max-width:767px) {

#enter-block-id-here>div {

text-align: center !important;

}

}

You need to replace this text "#enter-block-id-here" with the actual block ID you want it to apply to.

How to find the block ID:
https://squarefortytwo.com/squarespace-guides/find-an-id-in-squarespace-71

Hi there,
I'm using the blog-id, but I can't make this work. Do you have any other suggestions? Thanks a lot! 

@media screen and (max-width:767px) {

#block-2c06e5bedf7554ffcf3f>div {

text-align: center !important;

}

}

Website: www.possing.dk 

The code works just fine in my testing. Can you share the page you are trying to get this to work on?