A collection of tools that might be useful for you.
CSS style guide
Code that can be used on a page on your website installation to easily determine the current styles on many default items.
Calculator to estimate final charge in order to recover payment fees for Square, Stripe and PayPal Australia.
If you consider signing up to and use Square Payments you can use this link and Square will waive the transaction fees for the initial transactions up to a value of $1,000.