How to select an element by class in CSS?

Question

css

There is an element:
<span class='next prev'></span>
How in CSS can I select span by class next and prev?
This is for some moments when one class cannot be, but the other remains - to prescribe for each case.

Answer 1

.next, .prev {...} // или .next или .prev или оба
.next.prev { ... } // только оба
.next, .next.prev { ... } // .next или оба. Если будет только .prev - не сработает

Answer 2

.next, .prev {...}