Converting box-shadow, to a linear-gradient

[PaulOB]

It’s just a matter of using margin to create the right space.

.box6 {
  width: 0px;
  margin: 90px;
  box-shadow: 0 0 0 5px teal, 0 0 0 10px black, 0 0 0 15px orange,
    0 0 0 20px black, 0 0 0 25px teal, 0 0 0 30px black, 0 0 0 35px orange,
    0 0 0 40px black, 0 0 0 45px teal, 0 0 0 50px black, 0 0 0 55px orange,
    0 0 0 60px black, 0 0 0 65px teal, 0 0 0 70px black, 0 0 0 75px orange,
    0 0 0 80px black, 0 0 0 85px teal;
}