<link href='https://fonts.googleapis.com/css?family=Varela+Round' rel='stylesheet' type='text/css'>

<div class="button">
	<a href="#">
		Often Unseen 
		<span class="shift">›</span>
	</a>
	<div class="mask"></div>
</div>
:root {
	--bg-body: rgba(32, 32, 32, 1);
	--bg-body-image: radial-gradient(30% 90% ellipse at bottom center, rgba(0, 0, 0, 0), rgba(0, 0, 0, 1) 100%);
	--bg-body-hover: rgba(40, 40, 40, 1);
	--bg-button: rgba(255, 255, 255, 0);
	--bg-button-hover: rgba(255, 255, 255, 0.05);
	--bg-button-active: rgba(255, 255, 255, 1.0);
	--bg-mask: rgba(255, 255, 255, 0.5);
	--bg-mask-hover: rgba(255, 255, 255, 1.0);
	--border-button: rgba(255, 255, 255, 0.2);
	--border-button-hover: rgba(255, 255, 255, 1.0);
	--color-button: rgba(255, 255, 255, 0.6);
	--color-button-hover: rgba(255, 255, 255, 1.0);
	--color-button-active: var(--body-bg);
	--font-button: "Varela Round", sans-serif;
	--shadow-button-hover: 0 0 0.3125rem rgba(255, 255, 255, 0.8);
}

body {
	align-items: center;
	background-color: var(--bg-body);
	background-image: var(--bg-body-image);
	display: flex;
	height: 100vh;
	justify-content: center;
	margin: 0;
	padding: 0;
	transition: background-color 2s cubic-bezier(0.19, 1, 0.22, 1);
}

body.hover {
	background-color: var(--bg-body-hover);
}

.button {
	background-color: var(--bg-button);
	border: 0.125rem solid var(--border-button);
	cursor: pointer;
	letter-spacing: 0.2125rem;
	line-height: 1;
	overflow: hidden;
	padding: 1.25rem 1.875rem;
	position: relative;
	text-align: center;
	text-transform: uppercase;
	transition: 
		background-color 0.2s cubic-bezier(0.19, 1, 0.22, 1),
		border 1s cubic-bezier(0.19, 1, 0.22, 1),
		color 0.6s cubic-bezier(0.19, 1, 0.22, 1);
	user-select: none;
}

.button a {
	color: var(--color-button);
	font-family: var(--font-button);
	text-decoration: none;
	white-space: nowrap;
}

.button .mask {
	background-color: var(--bg-mask);
	height: 6.25rem;
	position: absolute;
	transform: translate3d(-120%, -50px, 0) rotate3d(0, 0, 1, 45deg);
	transition: all 1.1s cubic-bezier(0.19, 1, 0.22, 1);
	width: 12.5rem;
}

.button .shift {
	display: inline-block;
	transition: all 1.1s cubic-bezier(0.19, 1, 0.22, 1);
	vertical-align: text-top;
}

.button:hover {
	background-color: var(--bg-button-hover);
	border-color: var(--border-button-hover);
	box-shadow: var(--shadow-button-hover);
}

.button:hover a {
	color: var(--color-button-hover);
}

.button:hover .mask {
	background-color: var(--bg-mask-hover);
	transform: translate3d(120%, -100px, 0) rotate3d(0, 0, 1, 90deg);
}

.button:hover .shift {
	transform: translateX(0.3125rem);
}

.button:active {
	background-color: var(--bg-button-active);
}

.button:active a {
	color: var(--color-button-active);
}

/*
.button:hover {
	background-image: url('http://.com/img/codepen/savvy.jpg');
	background-position: center center;
	background-repeat: no-repeat;
	background-size: cover;
}
*/
const body = document.body;
const btn = document.querySelectorAll('.button')[0];

btn.addEventListener('mouseenter', () => {
	body.classList.add('hover');
});

btn.addEventListener('mouseleave', () => {
	body.classList.remove('hover');
});

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.