body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
}

header {
  background: #333;
  color: #fff;
  padding: 20px;
}

header nav a {
  color: #fff;
  margin-right: 15px;
  text-decoration: none;
}

main {
  padding: 20px;
}

table {
  border-collapse: collapse;
  width: 100%;
}

table, th, td {
  border: 1px solid #ccc;
}

th, td {
  padding: 10px;
}