Responsive tip app using Grid and StimulusJS

Implemented using StimulusJS for the logic (calculation and validations) along with grid for the layout. Decided to move the position of the error messages so that they were more flexible and consistent.

Probably spent as much time trying to cover as many edge cases, as I did with implementing the layout and main calculation logic. Some examples:

• if the user clicks in the custom tip field and clicks out without entering a figure, it should result in an error
• accepting the custom tip with a percentage sign like 20%
• if an error occurs display dashes in the results panel so a user is protected from using potentially incorrect figures (e.g. if a negative custom tip value is entered)

and lots more! :)