Bug I can’t continue

Tell us what’s happening:

Your code so far


<style>
 h4 {
   text-align: center;
   background-color: rgba(45, 45, 45, 0.1);
   padding: 10px;
   font-size: 27px;
 }
 p {
   text-align: justify;
 }
 .links {
   text-align: left;
   color: black;
opacity: 0,7;
 }
 #thumbnail {
   box-shadow: 0 10px 20px rgba(0,0,0,0.19), 0 6px 6px rgba(0,0,0,0.23);
 }
 .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">
 <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 (Macintosh; Intel Mac OS X 10_15) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.1 Safari/605.1.15.

Challenge: Decrease the Opacity of an Element

Link to the challenge:
https://www.freecodecamp.org/learn/responsive-web-design/applied-visual-design/decrease-the-opacity-of-an-element

You wrote 0,7 instead of 0.7
Change the comma to a full stop and it should work.

Thanks but I try still not working :pensive:

It shows you are using the Firefox browser to run your lesson. I had this similar issue on the exact lesson. log out of there, Jump over to Chrome browser and try there. That worked for a lot of us. good luck!