Not sure where im going wrong

THe form element should have the background color of green/

<link href="https://fonts.googleapis.com/css?family=Lobster" rel="stylesheet" type="text/css">
<style>
  .red-text {
    color: red;
  }

  h2 {
    font-family: Lobster, monospace;
  }

  p {
    font-size: 16px;
    font-family: monospace;
  }

  .thick-green-border {
    border-color: green;
    border-width: 10px;
    border-style: solid;
    border-radius: 50%;
  }

  .smaller-image {
    width: 100px;
  }

  .silver-background {
    background-color: silver;
  
  }
</style>

<h2 class="red-text">CatPhotoApp</h2>
<main>
  <p class="red-text">Click here to view more <a href="#">cat photos</a>.</p>

  <a href="#"><img class="smaller-image thick-green-border" src="https://bit.ly/fcc-relaxing-cat" alt="A cute orange cat lying on its back."></a>

  <div class="silver-background">
    <p>Things cats love:</p>
    <ul>
      <li>cat nip</li>
      <li>laser pointers</li>
      <li>lasagna</li>
    </ul>
    <p>Top 3 things cats hate:</p>
    <ol>
      <li>flea treatment</li>
      <li>thunder</li>
      <li>other cats</li>
    </ol>
  </div>

  <form action="https://freecatphotoapp.com/submit-cat-photo-form" id="cat-photo-form">"#cat-photo-element {background-color: green;
  }
    <label><input type="radio" name="indoor-outdoor" checked> Indoor</label>
    <label><input type="radio" name="indoor-outdoor"> Outdoor</label><br>
      **Your code so far**
      
```html

<link href="https://fonts.googleapis.com/css?family=Lobster" rel="stylesheet" type="text/css">
<style>
.red-text {
  color: red;
}

h2 {
  font-family: Lobster, monospace;
}

p {
  font-size: 16px;
  font-family: monospace;
}

.thick-green-border {
  border-color: green;
  border-width: 10px;
  border-style: solid;
  border-radius: 50%;
}

.smaller-image {
  width: 100px;
}

.silver-background {
  background-color: silver;

}
</style>

<h2 class="red-text">CatPhotoApp</h2>
<main>
<p class="red-text">Click here to view more <a href="#">cat photos</a>.</p>

<a href="#"><img class="smaller-image thick-green-border" src="https://bit.ly/fcc-relaxing-cat" alt="A cute orange cat lying on its back."></a>

<div class="silver-background">
  <p>Things cats love:</p>
  <ul>
    <li>cat nip</li>
    <li>laser pointers</li>
    <li>lasagna</li>
  </ul>
  <p>Top 3 things cats hate:</p>
  <ol>
    <li>flea treatment</li>
    <li>thunder</li>
    <li>other cats</li>
  </ol>
</div>

<form action="https://freecatphotoapp.com/submit-cat-photo-form" id="cat-photo-form">"#cat-photo-element {background-color: green;
}
  <label><input type="radio" name="indoor-outdoor" checked> Indoor</label>
  <label><input type="radio" name="indoor-outdoor"> Outdoor</label><br>
  <label><input type="checkbox" name="personality" checked> Loving</label>
  <label><input type="checkbox" name="personality"> Lazy</label>
  <label><input type="checkbox" name="personality"> Energetic</label><br>
  <input type="text" placeholder="cat photo URL" required>
  <button type="submit">Submit</button>
</form>
</main>
  **Your browser information:**

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0.

Challenge: Use an id Attribute to Style an Element

Link to the challenge:

It looks like you are trying maybe to do inline style formatting without including the style part.

In your form element, you have this portion :

#cat-photo-element {background-color: green;}

With the way it is formatted, it should be up top inside of your style element instead.
Also your ID needs to match the ID you defined in your form which is

id=“cat-photo-form”

To fix both, inside your style element up-top, place:

#cat-photo-form {
background-color: green;
}

Hope this helps!

Your CSS selectors need to be in the style section of your code.