html,body {
  margin: 0;
  padding: 0;
  width: 100%;
  height:100%;
}
body {
background-color: #ccddcc;
}
table {
  background-color: lightgreen;
  border: 1px solid green;
  border-radius: 1em;
  /*border-collapse: collapse;*/
  padding: 1em;
}
th,td {
  background-color: white;
  border: 1px solid orange;
  padding: 0.5em;
}
.main-col {
  width:800px;
  margin-left:auto;
  margin-right:auto;
  border-left:1px solid green; 
  border-right: 1px solid green;
  padding:1em;
  background-color:white;
}