How to centralize my collections list?

[WS_Materiais]

I would like to center my collection in the middle of the screen, how do I do it?
My website URL is https://wsmateriais.com

[Alex-A13]

Hi @WS_Materiais 
1- Go to Online Store > Themes > Actions > Edit Code.
In the left sidebar, open the theme.css or theme.scss.liquid file, or if those files don’t exist, look for styles.css.
Add the following CSS at the bottom of the file:
.collection-grid {
display: flex;
justify-content: center;
text-align: center;
}

Hope that helps!

[WS_Materiais]

Unfortunately it didn't work...