clients/web: fix auth modal width on medium screens

[vcashwin]

Fixing the size of auth modal on iPads, medium screens.

Before

After

[vercel]

@vcashwin is attempting to deploy a commit to the polar-sh Team on Vercel.

A member of the Team first needs to authorize it.

[vcashwin]

Hello @frankie567, as I was diving in Polar, something caught my eye. Would you be able to review the PR?

Thanks for the cool stuff you're building!

[shahida615]

Hello @frankie567, as I was diving in Polar, something caught my eye. Would you be able to review the PR?

Thanks for the cool stuff you're building!

[frankie567]

Thank you for taking time to look at this. Unfortunately, I can't accept it like this: now, it doesn't look good on large screens:

If you can tweak that so it still appears as currently on large screens, would be fine.