Help recreating Use a CSS Linear Gradient to Create a Striped Element in personal webpage

Tell us what’s happening:
Tried implementing this code in personal webpage but its not working pls what i’m i doing wrong

Your code so far


    border-radius: 20px;
    width: 70%;
    height: 400px;
    margin:  50 auto;
    background: repeating-linear-gradient(
      yellow 0px,
      yellow 40px,
      black 40px,
      black 80px



Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0.

Link to the challenge:

Your code pass for me, refresh your browser clear your cache and try again, use chrome if you are not on it.