layout.css

body {
	position:relative;
	top:0;
	left:0;
	width:100vw;
	min-height:100vh;
	margin:0;
	padding:0;
}

web-app {
	position:relative;
	left:0;
	width:100vw;
	height:100vh;
}

app-screen {
	position:absolute;
	top:0;
	left:0;
	width:100vw;
	min-height:100vh;
}

app-screen {
	display:none;
	left:-200vw;
}

app-screen[active=true] {
	display:block;
	left:0;
}