html, body{
  height: 100%;
  width: 100%;
    background-color: black;
    color: white;
}
textarea {
    background-color: black;
    color: white;
 }
    a:link, a:visited {
  background-color: blue;
  color: white;
  padding: 14px 25px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-family: Arial;
}
a:hover, a:active{
  background-color: green;
}
    button {
  background-color: blue;
  color: white;
  padding: 14px 25px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-family: Arial;
        font-size: 17px;
}
button:hover, button:active{
  background-color: green;
}
.cntr{
    text-align: center;
}
table, th, td {
  border:1px solid white;
    text-align: center;
}
table{
    margin-left:auto;
    margin-right:auto;
}