They sent me a link for an extra $5 off, so I am letting you know!
Not an affiliate link - I am just a user.
What is CSS Scan?
CSS Scan is a fast way to inspect and copy CSS. Just hover over anything on a website, and it will show you the CSS of that element.
You can copy this entire CSS with a single click.
There are of course alternative free ways of getting this information. But this tool makes it much more convenient.
It is pretty nifty. Try it, and if you like it, you can get it now for US $50, less 50%, less the extra US $5 in the link they sent me.
It is also doing well on Product Hunt:
https://www.producthunt.com/posts/css-scan-2-0
The developer is very active and making continual improvements, which you get for free.
Can't you just use the W3C free option at https://jigsaw.w3.org/css-validator/