Change Font Weight for Large Paragraph - 7.1

I'm trying to change the font weight just for Large Paragraph in 7.1. Below is the current code I've got in my Custom CSS;

––––––––––––––––

p.sqsrte-large {
     font-weight: 400;
 }

––––––––––––––––

However, the weight isn't changing, and it's only when I up it to 600 does it change to reflect that weight. Am I missing something?

Thanks in advance

Have you tried adding !important ?