Just HTML and CSS, I'm a noob yet!!!

Some recommendations regarding your code that could be of interest to you.

CSS

• If you want to center it easily, you can update your body in this way:

body {
  background-color: hsl(212, 45%, 89%);
  font-family: "Outfit", sans-serif;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

• if you use flexbox, you don't need to give margin to whitebox. This whitebox is the updated version:

.whitebox{            
    position: relative;
    height: 580px;
    max-width: 350px;  // max-width makes it responsive
    background-color: hsl(0, 0%, 100%);
    border-radius: 5%;
}

Hope I am helpful. :)

Hello! You did well on ur first challenge.

https://www.octobot.io/blog/html-accessibility/ Hope this article above will help you with fixing those accessibility reports.

And for centering the white container, I think flex-boxes is best way. Please take a look at those.

I’m still learning too. Have a nice day.