I can't seem to get passed this stage I can't figure out how to add/ complete this @keyframes

Your code so far

button {
  border-radius: 5px;
  color: white;
  background-color: #0F5897;
  padding: 5px 10px 8px 10px;

button:hover {
  animation-name: background-color #4791d0;
  animation-duration: 500ms;

100% {background-color #4791d0;}


<button class'background-color'>Register</button>

**Link to the challenge:**

You missed the part where you describe your problem and what you have tried :slight_smile:

Look closely at the example in the left panel. Notice that the @keyframes rule is given a name (width) and then that name is used for the animation-name property in the img:hover rule. In the right panel, the animation-name property already has the name set for you, so you just have to set the @keyframes rule to that name. And then make sure you remember all of your curly braces.