<link href='https://fonts.googleapis.com/css?family=Raleway:400,500,300' rel='stylesheet' type='text/css'>
<div id="mainButton">
	<div class="btn-text" onclick="openForm()">Sign In</div>
	<div class="modal">
		<div class="close-button" onclick="closeForm()">x</div>
		<div class="form-title">Sign In</div>
		<div class="input-group">
			<input type="text" id="name" onblur="checkInput(this)" />
			<label for="name">Username</label>
		</div>
		<div class="input-group">
			<input type="password" id="password" onblur="checkInput(this)" />
			<label for="password">Password</label>
		</div>
		<div class="form-button" onclick="closeForm()">Go</div>
		<div class="codepen-by">CodePen by Cole Waldrip</div>
	</div>
</div>
<div class="codepen-by">CodePen by Cole Waldrip</div>

$shadow1 : 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
$shadow2 : 0 3px 6px rgba(0,0,0,0.16), 0 3px 6px rgba(0,0,0,0.23);
$shadow3 : 0 10px 20px rgba(0,0,0,0.19), 0 6px 6px rgba(0,0,0,0.23);
$shadow4 : 0 14px 28px rgba(0,0,0,0.25), 0 10px 10px rgba(0,0,0,0.22);
$shadow5 : 0 19px 38px rgba(0,0,0,0.30), 0 15px 12px rgba(0,0,0,0.22);

@mixin transition($transition...) {
	-webkit-transition: $transition;
	-moz-transition: $transition;
	-ms-transition: $transition;
	-o-transition: $transition;
	transition: $transition;
}

@mixin transform($transform) {
	-webkit-transform: $transform;
	-moz-transform: $transform;
	-ms-transform: $transform;
	-o-transform: $transform;
	transform: $transform;
}

*, *:before, *:after {
	margin: 0;
	padding: 0;
	box-sizing: border-box;
}

body {
	color: #999;
	padding: 20px;
	display: flex;
	min-height: 100vh;
	align-items: center;
	font-family: 'Raleway';
	justify-content: center;
	background-color: #fbfbfb;
}

#mainButton {
	color: white;
	border: none;
	outline: none;
	font-size: 24px;
	font-weight: 200;
	overflow: hidden;
	position: relative;
	border-radius: 2px;
	letter-spacing: 2px;
	box-shadow: $shadow1;
	text-transform: uppercase;
	background-color: #00a7ee;
	@include transition(all 0.2s ease-in);
	
	.btn-text {
		z-index: 2;
		display: block;
		padding: 10px 20px;
		position: relative;
		
		&:hover {
			cursor: pointer;
		}
	}
	
	&:after {
		top: -50%;
		z-index: 1;
		content: '';
		width: 150%;
		height: 200%;
		position: absolute;
		left: calc(-150% - 40px);
		background-color: rgba(255,255,255,0.2);
		@include transform(skewX(-40deg));
		@include transition(all 0.2s ease-out);
	}
	
	&:hover {
		cursor: default;
		box-shadow: $shadow3;
		
		&:after {
			@include transform(translateX(100%) skewX(-30deg));
		}
	}
	
	&.active {
		box-shadow: $shadow5;
		
		.modal {
			@include transform(scale(1, 1));
		}
	}
	
	.modal {
		top: 0;
		left: 0;
		z-index: 3;
		width: 100%;
		height: 100%;
		padding: 20px;
		display: flex;
		position: fixed;
		align-items: center;
		justify-content: center;
		flex-direction: column;
		background-color: inherit;
		transform-origin: center center;
		background-image: linear-gradient(to top left, #00a7ee 10%, lighten(#00a7ee, 20%) 65%, white 200%);
		@include transform(scale(0.000001,0.00001));
		@include transition(all 0.2s ease-in);
	}
}

.close-button {
	top: 20px;
	right: 20px;
	position: absolute;
	@include transition(opacity 0.2s ease-in);
	
	&:hover {
		opacity: 0.5;
		cursor: pointer;
	}
}

.form-title {
	margin-bottom: 15px;
}

.form-button {
	width: 100%;
	padding: 10px;
	color: #00a7ee;
	margin-top: 10px;
	max-width: 400px;
	text-align: center;
	border: solid 1px white;
	background-color: white;
	@include transition(color 0.2s ease-in, background-color 0.2s ease-in);
	
	&:hover {
		color: white;
		cursor: pointer;
		background-color: transparent;
	}
}

.input-group {
	width: 100%;
	font-size: 16px;
	max-width: 400px;
	padding-top: 20px;
	position: relative;
	margin-bottom: 15px;
	
	input {
		width: 100%;
		color: white;
		border: none;
		outline: none;
		padding: 5px 0;
		line-height: 1;
		font-size: 16px;
		font-family: 'Raleway';
		border-bottom: solid 1px white;
		background-color: transparent;
		@include transition(box-shadow 0.2s ease-in);
		
		+ label {
			left: 0;
			top: 20px;
			position: absolute;
			pointer-events: none;
			@include transition(all 0.2s ease-in);
		}
		
		&:focus {
			box-shadow: 0 1px 0 0 white;
		}
		
		&:focus,
		&.active {
			+ label {
				font-size: 12px;
				@include transform(translateY(-20px));
			}
		}
	}
}

.codepen-by {
	left: 0;
	bottom: 0;
	width: 100%;
	padding: 10px;
	font-size: 16px;
	position: absolute;
	text-align: center;
	text-transform: none;
	letter-spacing: initial;
}

var button = document.getElementById('mainButton');

var openForm = function() {
	button.className = 'active';
};

var checkInput = function(input) {
	if (input.value.length > 0) {
		input.className = 'active';
	} else {
		input.className = '';
	}
};

var closeForm = function() {
	button.className = '';
};

document.addEventListener("keyup", function(e) {
	if (e.keyCode == 27 || e.keyCode == 13) {
		closeForm();
	}
});