"styles" configuration should not be used for internal lookup

[foobear]

When using the styles configuration option, I have to be very careful to not break Rome internals.
Apparently, configured class names are also used for internal logic to find elements in the picker.

Examples:

• space-separated strings
  Using Bootstrap 4 utility classes to define something like daySelected: 'background-primary text-white seems to work, but typing into the input field no longer deselects the previously selected date.
• Using the same class name for multiple elements
  Applying color via dayPrevMonth: 'text-muted', dayNextMonth: 'text-muted' makes clicking a day in the next month actually select the day from the previous month.

I've created a pen for both: https://codepen.io/foobear/pen/NmqOGG

[knorthfield]

Adding classes to timeOption or dayBodyElem also disables ability to pick a date or time.