Just specify the variable name in background property
For the curriculum titled: Use a custom CSS Variable,
I put the following code in all the places that say “change code below”
background: var(- -penguin-skin);
For the curriculum titled: Attach a Fallback value to a CSS Variable,
I put the following code:
background: var(- -penguin-skin, black);
I hope this helps someone.
**Note the dashes have an extra space in between. I do not recommend copying and pasting my code.