I'm trying to learn HTML and CSS but I have encountered a problem:

```
<style style="text/css">
    div.slide-slow {
        width: 100%;
        overflow: hidden;
    }

    div.slide-slow div.inner {
        animation: slide-slow 30s;
        margin-top: 0%;
    }

    @keyframes slide-slow {
        from {
            margin-left: 100%;
        }

        to {
            margin-left: 0%;
        }
    }
</style>

<div class="slide-slow">
    <div class="inner">
        <img src="http://www.html.am/images/html-codes/marquees/fish-swimming.gif" alt="Swimming fish">
    </div>
</div>

```

I want this CSS to loop and not just stop when it is done. Is it possible to make a CSS function to loop?