calculator.css

body {
	font-family: -apple-system, BlinkMacSystemFont, system, sans-serif;
}

.text {
	width: 320px;
	margin: 70px auto 30px;
	text-align: center;
	line-height: 1.4;
}
h1 {
	font-size: 22px;
}

main {
	background: #8E8E8E;
	border-radius: 5px;
	width: 243px;
	margin: 30px auto;
	box-shadow: 1px 1px 6px 2px rgba(168,168,168,1);
}

output {
	background: #4C4C4C;
	border-radius: 5px 5px 0 0;
	font-weight: 100;
	color: #FFF;
	display: block;
	font-size: 44px;
	line-height: 44px;
	text-align: right;
	padding: 20px 10px 10px 10px;
}
output.small-text {
	font-size: 22px;
}
output.extra-small-text {
	font-size: 12px;
}

.button-row:before,
.button-row:after {
	content: ' ';
	display: table;
}
.button-row:after {
	clear: both;
}

button {
	height: 50px;
	width: 60px;
	font-size: 22px;
	font-weight: 300;
	border: none;
	margin: 0;
	display: block;
	float: left;
	background: rgba(224, 224, 224, 1.00);
	margin: 0 1px 1px 0;
}
button:last-child {
	margin-right: 0;
}
.button-row:last-child button {
	margin-bottom: 0;
}
.button-row:last-child button:first-child {
	border-radius: 0 0 0 5px;
}
.button-row:last-child button:last-child {
	border-radius: 0 0 5px 0;
}
button:focus,button:active {
	outline: none;
	background: rgba(212, 212, 212, 0.5);
}
button.meta {
	background: rgba(214, 214, 214, 1);
}
button.meta:focus, button.meta:active {
	background: rgba(214, 214, 214, 0.5);
}
button.operator {
	background: rgba(247, 147, 49, 1);
	color: #FFF;
	font-weight: 100;
}
button.operator:focus, button.operator:active {
	background: rgba(190, 111, 33, 1);
}
button.plus-minus {
	position: relative;
}
button.plus-minus span {
	font-size: 15px;
	position: absolute;;
}
button.plus-minus .plus {
	left: 20px;
	top: 10px;
}
button.plus-minus .minus {
	right: 20px;
	top: 18px;
}
button.zero {
	width: 121px;
	text-align: left;
	padding-left: 23px;
}