I need help here please!

Tell us what’s happening:
Describe your issue in detail here.

The code for class one seems not to be working

  **Your code so far**
/* file: index.html */
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Colored Markers</title>
  <link rel="stylesheet" type="text/css" href="styles.css">
</head>
<body>
  <h1>CSS Color Markers</h1>
  <div class="container">
    <div class="marker one">
    </div>
    <div class="marker">
    </div>
    <div class="marker">
    </div>
  </div>
</body>
</html>
/* file: styles.css */
h1 {
text-align: center;
}

.marker {
width: 200px;
height: 25px;
margin: 10px auto;
}

one {
background-color="red";
}

Challenge: Step 18

Link to the challenge:

This is selecting “one” elements as opposed to “one” classes.

Remember that in CSS a period is required to indicate a class. For example:

.make_red {
    color: red;
}

Would make this red:

<p class="make_red"> Text </p>

I still haven’t figured it out pls

basically in this step you have to create a class called “red”. you can just follow the syntax for creating class “marker” to create class “red”. The syntax would be something like this:

.class-name{
   // code
}