I really don't know wat I'm doing wrong here please help

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

  **Your code so far**

<style>
h4 {
  text-align: center;
  background-color: rgba(45, 45, 45, 0.1);
  padding: 10px;
  font-size: 27px;
}
.thumbnail {box-shadow:0 10px 20px rgba( 0,0,0,0.19), 0 6px 6px rgba( 0,0,0,0.23);}
p {
  text-align: justify;
}
.links {
  text-align: left;
  color: black;
}



.fullCard {
  width: 245px;
  border: 1px solid #ccc;
  border-radius: 5px;
  margin: 10px 5px;
  padding: 4px;
}
.cardContent {
  padding: 10px;
}
.cardText {
  margin-bottom: 30px;
}
</style>
<div class="fullCard" id="thumbnail box-shadow">

<div class="cardContent">
  <div class="cardText">
    <h4>Alphabet</h4>
    <hr>
    <p><em>Google was founded by Larry Page and Sergey Brin while they were <u>Ph.D. students</u> at <strong>Stanford University</strong>.</em></p>
  </div>
  <div class="cardLinks">
    <a href="https://en.wikipedia.org/wiki/Larry_Page" target="_blank" class="links">Larry Page</a><br><br>
    <a href="https://en.wikipedia.org/wiki/Sergey_Brin" target="_blank" class="links">Sergey Brin</a>
  </div>
</div>
</div>
  **Your browser information:**

User Agent is: Mozilla/5.0 (Linux; Android 10; V2027) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.99 Mobile Safari/537.36

Challenge: Add a box-shadow to a Card-like Element

Link to the challenge:

You didn’t tell us what is going on. Please edit your post so that we know how to help you.

Yes, as @ArielLeslie said, you need to explain what’s going on. At least explain what you think the problem is and what you tried doing in order to solve it.

Look at the html element that you modified:

<div class="fullCard" id="thumbnail box-shadow">

The instructions are:

The element now has an id of thumbnail . With this selector, use the example CSS values above to place a box-shadow on the card.

box-shadow is a CSS property. You can set its values using the id selector #thumbnail.

If I had a div with an id of myThumbnail, I could set the value of its CSS property background-color as follows:

<style>
    #myThumbnail {
       background-color: #f7f7f7;
   }
</style>
<div id="myThumbnail">
    
</div>

Notice that the id selector has a hash symbol (#).