h1   {text-align:center;}

table, th, td {
  border: 1px solid black;
  border-collapse: collapse;
}

ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: #333333;
}

li {
  float: left;
}

li a {
  display: block;
  color: white;
  text-align: center;
  padding: 16px;
  text-decoration: none;
}

li a:hover {
  background-color: #111111;
}

.header {
    background-color: white; color:#333333;
}

.main {
    background-color: white; color:#333333;
}

.footer {
    background-color: #333333; color:white;
}