If you have trouble with the size of cards, scoreboard, or anything else at the site, it could be because your screen resolution is not entirely compatible with the site, which tends to favor a higher screen resolution.
If you send me a bug report about a problem like this, I'd really appreciate it if you visit Support Details, which will show your screen resolution and other info, and then put my email address - marya@worldofcardgames.com - into their text input and have them send that info to me. It can help me figure out what is going wrong for you.
It's also super helpful if you can send me a screenshot.
Another possibility is that the "zoom" level is set too high (or too low) on your browser. For most browsers, you can reset the zoom level to zero by visiting the website, and then hitting the Ctrl+0 keys together (Ctrl key together with the number zero).