Build a Technical Documentation Page

My code is not passing this “Your “#navbar” should always be on the left edge of the window.” due to: left: -140px.and I don’t know why.

@media screen and (max-width: 900px) {
  #main-doc {
    margin-left: 40px;
  }

  #navbar {
    position: fixed;
    left: -140px;
    transition: 0.3s;
    width: 100px;
  }

  #navbar:hover {
    left: 0;
  }
}

Try it with positive value for the left property.