Issue with tests on Basic CSS: Attach a Fallback value to a CSS Variable

Tell us what’s happening:
I’ve set the background’s default value to black, as per the test Apply the fallback value of black to the background property of the penguin-top class. However, that test is not passing.
(I know that pengiun-ski is spelt wrong, but that’s part of the challenge).

.penguin-top {
    top: 10%;
    left: 25%;
    /* change code below */
    background: var(--pengiun-ski, black);
    /* change code above */
    width: 50%;
    height: 45%;
    border-radius: 70% 70% 60% 60%;

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.87 Safari/537.36.

Link to the challenge:

Although it’s not part of the requirements, you still need to spell it correctly so that you can pass the test cases.

–pengiun-ski is supposed to be spelt wrong. It’s part of the test