body {
  font-family: Arial, sans-serif;
  line-height: 1.6;
  background-color: #f4f4f4;
  color: #333;
  margin: 0;
  padding: 0;
}
header {
  background: #417d5a;
  color: #fff;
  padding: 1em;
  text-align: center;
}
main {
  padding: 2em;
}
button {
  background-color: #417d5a;
  color: white;
  border: none;
  padding: 10px 20px;
  cursor: pointer;
}
button:hover {
  background-color: #365f49;
}