html {
	box-sizing: border-box;
	background: #55cfcf;
	font-family: 'helvetica neue';
	font-size: 20px;
	font-weight: 200;
}
  
body {
	margin: 0;
}
  
*, *:before, *:after {
	box-sizing: inherit;
}

.panels {
	min-height: 100vh;
	overflow: hidden;
	display: flex;
}

.panel {
	background: rgb(144, 212, 104);
	box-shadow: inset 0 0 0 5px rgba(255,255,255,0.1);
	color: white;
	text-align: center;
	align-items: center;
	transition:
	  font-size 0.7s cubic-bezier(0.61,-0.19, 0.7,-0.11),
	  flex 0.7s cubic-bezier(0.61,-0.19, 0.7,-0.11),
	  background 0.2s;
	font-size: 20px;
	background-size: cover;
	background-position: center;
	flex: 1;
	justify-content: center;
	display: flex;
	flex-direction: column;
}

.panel1 { 
	background-image:url(https://source.unsplash.com/gYl-UtwNg_I/1500x1500); 
}

.panel2 { 
	background-image:url(https://source.unsplash.com/rFKUFzjPYiQ/1500x1500); 
}

.panel3 { 
	background-image:url(https://images.unsplash.com/photo-1465188162913-8fb5709d6d57?ixlib=rb-0.3.5&q=80&fm=jpg&crop=faces&cs=tinysrgb&w=1500&h=1500&fit=crop&s=967e8a713a4e395260793fc8c802901d); 
}

.panel4 { 
	background-image:url(https://source.unsplash.com/ITjiVXcwVng/1500x1500); 
}

.panel5 { 
	background-image:url(https://source.unsplash.com/3MNzGlQM7qs/1500x1500); 
}

/* Flex Items */
.panel-item {
	margin: 0;
	width: 100%;
	transition: transform 0.5s;
	flex: 1 0 auto;
	display: flex;
	justify-content: center;
	align-items: center;
	text-transform: uppercase;
	font-family: 'Amatic SC', cursive;
	text-shadow: 0 0 4px rgba(0, 0, 0, 0.72), 0 0 14px rgba(0, 0, 0, 0.45);
	font-size: 2em;
}

.panel > *:first-child { 
	transform: translateY(-100%); 
}

.panel.open-active > *:first-child { 
	transform: translateY(0); 
}

.panel > *:last-child { 
	transform: translateY(100%); 
}

.panel.open-active > *:last-child { 
	transform: translateY(0); 
}
  
.font-big {
	font-size: 4em;
}

.panel.open {
	flex: 5;
	font-size: 40px;
}
  
@media only screen and (max-width: 600px) {
	.panel-item {
		font-size: 1em;
	}
}