.screen {
	display: flex; 
	justify-content: center; 
}

.container { 
	border: solid gray 1px;
	background-color: lightgray; 
	width: 300px;
	position: absolute;
	top: 50%;
	left: 50%;
	-ms-transform: translate(-50%, -50%);
	transform: translate(-50%, -50%);
}

.container div {
	margin: 50px;
}

.container div > * {
	margin: 0 0 20px 0;
}

@media only screen and (max-width: 600px) {
	.container {
	  width: 100%;
	}
  }