Your colleague wrote both HTML and CSS, but something is wrong.
Apparently he forgot to link styles to the HTML document.
You should fix this by properly linking styles.css to index.html

This task is part of the Full-Stack JavaScript Course
If you have any issues with it, you can ask for community help below the post
Feel free to help others if you’ve already solved the task

index.html

<!DOCTYPE html>
<html>
  <head>
    <title>History</title>
  </head>
  <body>
    <h1>History of programming languages</h1>
    <p>The first high-level programming language was Plankalkül, created by Konrad Zuse between 1942 and 1945.</p>
    <p>The first commercially available language was FORTRAN (FORmula TRANslation), developed in 1956.</p>
  </body>
</html>

styles.css

h1 {
    text-align: center;
}

p {
    color: olivedrab;
}