Ionic content change style

hi i use ionic cdn in my site
https://vipage.vivbook.com/lianaox/

the first problem is it doesn’t have scrolbar
then i got that it is because i didn’t use ion content tag

how can i change ion content style ?
to this


ion-content{
		
	background: linear-gradient(-45deg, #ee7752, #e73c7e, #23a6d5, #23d5ab);
	background-size: 400% 400%;
	animation: gradient 15s ease infinite;
}

@keyframes gradient {
	0% {
		background-position: 0% 50%;
	}
	50% {
		background-position: 100% 50%;
	}
	100% {
		background-position: 0% 50%;
	}
}