Your code looks correct for centering the rich text on mobile devices. However, if it’s not working, replace the previous CSS with the below CSS to override any other styles:
@media screen and (max-width: 749px) {
.rich-text__blocks.left {
text-align: center !important;
}
}
Also, note that without the @media query, the text alignment would apply to all screen sizes, not just mobile. Let me know if you need further adjustments!