code blocks don't render monospace font on non-windows system

code blocks display like this on mac os, on all browsers (tested safari, firefox and chrome). i'm fairly confident it also happens on android and linux but will test later

<img width="668" height="544" alt="Image" src="https://github.com/user-attachments/assets/944baffd-62b8-402d-97b5-e14128e7f484" />