styles.css

@charset 'utf-8';
@import url('//brick.a.ssl.fastly.net/Vollkorn:500');

* { border:  none;  margin: 0; font-weight: inherit; text-decoration: inherit;
    outline: none; padding: 0; font-family: inherit; font-size: 1em;         }

/* Colours for now: http://ethanschoonover.com/solarized */

body {
	font-family: Vollkorn, serif;
	font-size: 20px;
	text-align: center;
	background: #073642;
	color: #EEE8D5;
	display: flex;
	height: 100vh;
	flex-direction: column;
	justify-content: space-between;
	}

::-moz-selection { background: #002B36; color: currentColor; }
::selection { background: #002B36; color: currentColor; }

a {
	color: currentColor;
	}

h1, nav {
	padding: .5rem;
	font-size: .8rem;
	}

#game #word {
	font-size: 4rem;
	line-height: 1em;
	}

#game input {
	display: none;
	}

#game input + label {
	border: solid .2rem currentColor;
	display: inline-block;
	width: 5rem;
	height: 5rem;
	line-height: 5rem;
	text-align: center;
	font-size: 2rem;
	cursor: pointer;
	margin: 3rem 1rem;
	vertical-align: baseline;
	transition: all .2s;
	}
	
#game input#n + label {
	border-radius: 50%;
	}

#game input#t + label {
	width: 4.5rem;
	height: 4.5rem;
	line-height: 4.5rem;
	}
	
#game input:hover + label,
#game input:focus + label
#game input + label:hover {
	transform: scale(1.05);
	}

#game input:checked + label {
	transform: scale(1.05);
	background: black;
	position: relative;
	}

#game input[data-answer='wrong']:checked + label {
	border-color: #DC322F;
	background: #DC322F;
	}

#game input[data-answer='right']:checked + label {
	border-color: #859900;
	background: #859900;
	}

@keyframes result {
	0% {
		transform: translatey(0);
		opacity: 0;
	}
  
	50% {
		opacity: 1;
	}

	100% {
		transform: translatey(-1rem);
		opacity: 0;	
	}
}

#game input:checked + label:after {
	position: absolute;
	top: -60%;
	left: -2em;
	right: -2em;
	font-size: .8rem;
	text-transform: uppercase;
	text-align: center;
	pointer-events: none;
	animation: result 1s forwards;
	}
	
#game input[data-answer='wrong']:checked + label:after {
	content: 'Forkert';
	color: #DC322F;
	}
	
#game input[data-answer='right']:checked + label:after {
	content: 'Korrekt';
	color: #859900;
	}

#next {
	background: #002B36;
	cursor: pointer;
	padding: 1rem 2rem;
	color: currentColor;
	transition: all .2s;
	}
	
#next:hover,
#next:focus {
	transform: scale(1.05);
	outline: 0;
	}
	
#next.hidden {
	opacity: 0;
	pointer-events: none;
	}
	
#next:not(.hidden) {
	transition: opacity .4s .5s, transform .2s;
	}