body {
  margin: 0;
  font-family: Roboto, Arial, sans-serif;
  background-color: #f5f5f5;
  color: #212121;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 16px;
  box-sizing: border-box;
}

nav {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
  max-width: 400px;
}

nav a {
  text-decoration: none;
  color: #212121;
  background-color: #ffffff;
  padding: 24px 0;
  margin: 16px 0;
  width: 95%;
  text-align: center;
  border-radius: 12px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
  font-size: 20px;
  transition: background-color 0.2s;
}

nav a:hover {
  background-color: #e0e0e0;
}

@media (min-width: 1080px) {
  nav {
    max-width: 600px;
  }
  nav a {
    font-size: 22px;
    padding: 28px 0;
  }
}