When I typed 'border-style' in exercise and answered it says wrong but 'border-style' was green....

Answer 1

Rum bler Values for the `border-style` property indicate styles like solid, dotted, double, dashed, none, etc.

Color is assigned to the `border-color` property.

Answer 2

border: border-width border-style border-color;

Here's a good article for borders in-depth.
https://css-tricks.com/almanac/properties/b/border/

This is a demo code for showing various border-style by @Gaurav Vasant Gaurav.

https://code.sololearn.com/WtlCmYmqhVxu/?ref=app