What is the right answer?
What code have you tried. We are not just going to give you the answer. You have to show some work or ask questions about what specifically you do not understand. Then, we will attempt to guide you to the correct solution.
margin: 50px auto;
background: linear-gradient(35deg, red, yellow, #CCFFFF);
You have not given the correct values into the
background: property. They did not mention any red or yellow to be added, they have given instruction to add those two hex values they specified.