table.center {
  margin-left: auto; 
  margin-right: auto;
}

th, td {
	font-family: Helvetica, Arial, sans-serif;
	font-size: 12px;
	padding: 5px;
}

th {
	padding-top: 5px;
	padding-bottom: 5px;
	text-align: left;
	background-color: #4CAF50;
	position: sticky;
	top: 0;
	box-shadow: 0 3px 2px -1px rgba(0, 0, 0, 0.4);
}

#tr:nth-child(even){background-color: #f2f2f2;}

tr:hover {background-color: #ddd;}

h1 {
	font-family: Helvetica, Arial, sans-serif;
	font-size: 3vw;
	color: black;
	text-shadow: 2px 2px dimgrey;
	text-align: center;
}

footer {
	position: sticky;
	left: 0;
	right: 0;
	bottom: 0;
	height: 120px;
	padding: 3px;
	width: 100%;
	background-color: #4CAF50;
	font-family: Helvetica, Arial, sans-serif;
	text-align: center;
	box-shadow: 0 -3px 2px -1px rgba(0, 0, 0, 0.4);
}


/*div classes*/

.container {
	position: relative;
	display: flex;
	align-items: center;
	justify-content: center;
	width: 100%;
}

* {
	box-sizing: border-box;
}

.centered {
	position: absolute;
	top: 50%;
	left: 50%;
	transform: translate(-50%, -50%);
}