body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  text-align: center;
  margin: 0;
  padding: 0;
  background-color: #f9f9ff;
  color: #222;
}

header {
  background-color: #007bff;
  color: white;
  padding: 20px 10px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

h1 {
  margin: 0;
  font-size: 1.8em;
}

nav {
  margin-top: 10px;
}

button {
  background-color: white;
  border: 2px solid #007bff;
  color: #007bff;
  margin: 5px;
  padding: 10px 20px;
  border-radius: 8px;
  cursor: pointer;
  transition: 0.3s;
  font-weight: bold;
}

button:hover {
  background-color: #007bff;
  color: white;
}

main {
  padding: 20px;
}