
<ons-page>
<style>

#sky {

overflow: hidden;
height:100%;
}
#clouds {

width: 200%;
height: 600px;
background-image: url('https://clipground.com/images/background-cloud-clouds-clipart-8.jpg');
background-size: cover;
-webkit-animation: movingclouds 10s linear infinite;
-moz-animation: movingclouds 10s linear infinite;
-o-animation: movingclouds 10s linear infinite;
}
@keyframes movingclouds {
0% {margin-left: 0%;}
100% {margin-left: -100%;}
}
</style>

<div id="sky">
<div id="clouds"></div>
</div>

</ons-page>