Hi there! Please check out my code!
https://glitch.com/edit/#!/oxidized-rift-summer?path=style.css%3A68%3A1
Here is the task.
https://developer.mozilla.org/en-US/docs/Learn/CSS/CSS_layout/Fundamental_Layout_Comprehension
Thank you in advance!
Great work, @Mykyta_22!
All your CSS is correct. 
In your index.html you wrote <link href="styles.css" rel="stylesheet" type="text/css"> while the CSS file is called style.css. This prevents the style from being used on Glitch.
By the way: On Glitch you can upload assets (like images) and then use them in your code.
See you,
Michael