Question: I have this animation of a heart and I have the "beating" pretty refined. 

<http://codepen.io/wesbos/pen/tyqeL>

Problem is that it snaps to the beginning where I want it to be continuous and smooth. How can I fix this?

Answer: 
First and the final keyframes should have the same value. 
Add more keyframes so the animation is perfect

[CodePen](http://codepen.io/anon/pen/Dpivs)
You are having that last jump because you have the 100% set to 400px and then start again from 100px.
Try the following:

```
 100% {
     font-size:100px;
 }

```

You can also try adding the 'alternate' for the animation direction, like this:

```
-webkit-animation:snow 1s linear infinite alternate;

```

Hope it helps.