Freecodecamp still treats the code as wrong when it's right

[codediode]

hello
I’ve been having this issue with the website: I write the code 100% right and click on “run test” but the compiler says it is wrong . this happened twice in the applied visual design section . I thought there’s something wrong with my code maybe an invisible comma in the wrong place so I copied the solution and pasted it but it’s still wrong for some reason. I refreshed the page , I closed the website , I updated the browser, reset the code and nothing worked.
this happened in the hover part and the complementary colors part now.
Note that I’m having this problem only on Xubunto on virtual box ;when I paste the code on the SAME browser but on windows it works just fine!

my code so far:

<style>
body {
  background-color: #FFFFFF;
}
 .blue {
  background-color: blue;
}
.yellow {
  background-color: yellow;
}
div {
  display: inline-block;
  height: 100px;
  width: 100px;
}
</style>
<div class="blue"></div>
<div class="yellow"></div>

User Agent is: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0

Challenge: Learn about Complementary Colors

Link to the challenge:
https://www.freecodecamp.org/learn/responsive-web-design/applied-visual-design/learn-about-complementary-colors

[JeremyLT]

This code does pass for me. Are you using any browser extensions? Note the instructions

Note: Some browser extensions, such as ad-blockers and dark mode extensions can interfere with the tests. If you face issues, we recommend disabling extensions that modify the content or layout of pages, while taking the course.

[codediode]

I was using dark reader , I disabled it now and it worked ! thank you so much !

[JeremyLT]

There is a dark mode setting in the menu so that you don’t have to stare at a bright white screen.