dash-website/_sass/_overlay-menu.scss

.container {
	position: absolute;
	width: 100%;
	height: 100%;
	text-align: center;
	top: 40%;
	left: 0;
	margin: 0 auto;
	p {
		font-size: 18px;
	}
	a {
		display: inline-block;
		position: relative;
		text-align: center;
		color: #FF5252;
		text-decoration: none;
		font-size: 18px;
		overflow: hidden;
		top: 5px;
	}
	a:after {
		content: '';
		position: absolute;
		background: #FF5252;
		height: 2px;
		width: 0%;
		transform: translateX(-50%);
		left: 50%;
		bottom: 0;
		transition: .35s ease;
	}
	.a:hover:after, a:focus:after, a:active:after {
		width: 100%;
	}
}

#hero{
	.button_container {
		position: absolute;
		top: 40px;
		right: 30px;
		height: 23px;
		width: 32px;
		cursor: pointer;
		z-index: 100;
		transition: opacity .25s ease;
		&:hover {
			opacity: .7;
		}
		span {
			background: $white;
			border: none;
			height: 4px;
			width: 100%;
			position: absolute;
			top: 0;
			left: 0;
			transition: all .35s ease;
			cursor: pointer;
		}
		span:nth-of-type(2) {
			top: 8px;
		}
		span:nth-of-type(3) {
			top: 16px;
		}
	}

	.button_container.active .top {
		transform: translateY(8px) translateX(0) rotate(45deg);
		background: $white;
	}
	.button_container.active .middle {
		opacity: 0;
		background: $white;
	}
	.button_container.active .bottom {
		transform: translateY(-8px) translateX(0) rotate(-45deg);
		background: $white;
	}
}

.button_container {
	position: absolute;
	top: 30px;
	right: 30px;
	height: 23px;
	width: 32px;
	cursor: pointer;
	z-index: 100;
	transition: opacity .25s ease;
	&:hover {
		opacity: .7;
	}
	span {
		background: $blue;
		border: none;
		height: 4px;
		width: 100%;
		position: absolute;
		top: 0;
		left: 0;
		transition: all .35s ease;
		cursor: pointer;
	}
	span:nth-of-type(2) {
		top: 8px;
	}
	span:nth-of-type(3) {
		top: 16px;
	}

}

.button_container.active .top {
		transform: translateY(8px) translateX(0) rotate(45deg);
		background: $blue;
}
.button_container.active .middle {
	opacity: 0;
	background: $blue;
}
.button_container.active .bottom {
	transform: translateY(-8px) translateX(0) rotate(-45deg);
	background: $blue;
}

.overlay {
	position: fixed;
	background: $black;
	top: 0;
	left: 0;
	width: 100%;
	height: 0%;
	opacity: 0;
	visibility: hidden;
	transition: opacity .35s, visibility .35s, height .35s;
	overflow: hidden;

	.logo {
		width: 180px;
		height: auto;
		top: 30px;
		left: 30px;
		position: absolute;
	}

	nav {
		position: relative;
		height: 70%;
		top: 50%;
		transform: translateY(-50%);
		font-size: 36px;
		font-weight: 200;
		text-align: center;
	}

	ul {
		list-style: none;
		padding: 0;
		margin: 0 auto;
		margin-top: 0px;
		display: inline-block;
		position: relative;
		height: 50%;
		li {
			display: block;
			height: 16%;
			height: calc(100% / 6);
			min-height: 50px;
			position: relative;
			opacity: 0;
		}
		a {
			display: block;
			position: relative;
			color: $white;
			text-decoration: none;
			overflow: hidden;
			padding-bottom: 15px;
			padding-top: 5px;
		}
		a:hover:after, a:focus:after, a:active:after {
			width: 100%;
		}
	}

	.sign-up-btn {
		border: none;
		padding: 30px;
		color: $green !important;
		&:hover {
			background: none !important;
			color: $green !important;
		}
	}
}
.overlay.open {
	opacity: 1;
	visibility: visible;
	height: 100%;
	li {
		animation: fadeInRight .5s ease forwards;
		animation-delay: .35s;
	}
	li:nth-of-type(2) {
		animation-delay: .4s;
	}
	li:nth-of-type(3) {
		animation-delay: .45s;
	}
	li:nth-of-type(4) {
		animation-delay: .50s;
	}
}

@keyframes fadeInRight {
	0% {
		opacity: 0;
		left: 20%;
	}
	100% {
		opacity: 1;
		left: 0;
	}
}