* rename BetRow -> BetButton
* Replace bet modal in embed with inline betting
- Also simplifies graph height calculation
* Move bet row above graph, in "mini modal"
* Show signup button if not signed up
* Show probability change
* Show error after modal
- Show balance if insufficient funds
- Clear error from amount input if amount deleted entirely
* Fix error state conditions
- Reset amount input on success
- Reset success state on user input
* Make input smaller (80px)
