animation-step-direction.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Step animation direction</title>
<style type="text/css">
html {background: silver;}
body {background: white; margin: 1em; padding: 1em;}
.diagram {height: 100px; width: 1000px;
	background: linear-gradient(to right,
	#CCC 10%, 10%, 
	#BBB 20%, 20%,
	#AAA 30%, 30%,
	#999 40%, 40%,
	#888 50%, 50%,
	#777 60%, 60%,
	#666 70%, 70%,
	#555 80%, 80%,
	#444 90%, 90%,
	#333 100%
	);}
.label {text-align: center; font: 2em Arvo, serif;}
code {font: 1em monospace, serif;}
section .label {background: url(i/anim-arrow.png) no-repeat 0 100% / 900px 40px;
	width: 1000px; padding: 30px 0; margin: 0;}
#dg02 + .label {background-position: 100px 0;}

body:hover {background: #FFE;}
body:hover * {animation-play-state: paused;}
.stepanim {height: 100px; width: 100px;
	background: green; color: white; display: flex;
	justify-content: center; align-items: center; font: 2em Arvo, serif;
	animation: stepcolor 7.5s steps(9,end) forwards, stepmove 7.5s steps(9,end) forwards;}
#an02 {animation-timing-function: steps(9,start), steps(9,start);}
@keyframes stepcolor {
	from {background: #CCC;}
	to {background: #333;}
}
@keyframes stepmove {
	from {margin-left: 0;}
	to {margin-left: 900px;}
}

</style>
</head>
<body>
<p class="label">Hover the mouse pointer over the <code>body</code> (the white area) to pause animations.  Reload to restart them.</p>

<section>

<p class="label">end</p>
<div id="dg01" class="diagram"></div>

<div id="an01" class="stepanim">end</div>
<div id="an02" class="stepanim">start</div>

<div id="dg02" class="diagram"></div>
<p class="label">start</p>

</section>


</body>
</html>