please this code seem not to be working for me, what do i do please

h4 {
  text-align: center;
  background-color: rgb(45, 45, 45, 0.1);
  padding: 10px;

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;
<div class="fullCard">
<div class="cardContent">
  <div class="cardText">
    <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 class="cardLinks">
    <a href="" target="_blank" class="links">Larry Page</a><br><br>
    <a href="" target="_blank" class="links">Sergey Brin</a>

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:74.0) Gecko/20100101 Firefox/74.0.

Challenge: Adjust the background-color Property of Text

Link to the challenge:

background-color: rgb + “a”

Hello, I think there’s nothing wrong with your code. I try with codepen and it’s working. The “a” in rgba doesn’t really matter. Maybe you can adjust the “a” > 0.1 to see the color change.

Your code should add a background-color property to the h4 element set to rgba(45, 45, 45, 0.1) .

there is a character of difference in your code. add that a