html, body {
	margin: 0px; 
	padding: 0px;
	height: 100%;
background:#dedede;
}

h1{
	font-size:24px;
	padding:20px 0;
	font-weight:700;
	text-align:center;
color:#333;
	font-family:"Helvetica Neue", Helvetica, Arial, sans-serif;
}

.knoppen {
padding-bottom:5px;
}

.top {
height:20%;
}

 input{
  border:0px;
  -webkit-border-radius: 28;
  -moz-border-radius: 28;
  border-radius: 28px;
  font-family: Arial;
  color: #ffffff;
  font-size: 16px;
  background: #87D37C;
  padding: 10px 20px 10px 20px;
  text-decoration: none;
}

input:hover {
  background: #9ce890;
  text-decoration: none;
}