body {
  font-family: 'Segoe UI', Arial, sans-serif;
  margin: 0;
  background: #f7f7f7;
  color: #222;
}
header {
  background: #1e90ff;
  color: #fff;
  padding: 1rem 2rem;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}
header h1 {
  margin: 0 0 0.5rem 0;
}
nav#main-menu {
  margin-top: 0.5rem;
}
nav#main-menu a {
  color: #fff;
  text-decoration: none;
  margin-right: 1.5rem;
  font-weight: 500;
  transition: text-decoration 0.2s;
}
nav#main-menu a:hover {
  text-decoration: underline;
}
main#main-content {
  max-width: 900px;
  margin: 2rem auto;
  background: #fff;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.07);
  padding: 2rem;
}
footer {
  text-align: center;
  padding: 1rem;
  background: #222;
  color: #fff;
  margin-top: 2rem;
}
@media (max-width: 700px) {
  main#main-content {
    padding: 1rem;
  }
  header {
    padding: 1rem;
  }
}