body {
  background-color: #001a00;
  color: #00ff66;
  font-family: monospace;
  margin: 0;
  padding: 20px;
}

header h1 {
  text-align: center;
  font-size: 2rem;
}

.main-img {
  width: 100%;
  max-width: 350px;
  border: 3px solid #00ff66;
  display: block;
  margin: 20px auto;
}

nav {
  margin-top: 20px;
  text-align: center;
}

nav a {
  color: #00ffcc;
  margin: 0 10px;
  text-decoration: none;
  font-size: 1.2rem;
}

p {
  text-align: center;
  padding: 0 10px;
}

@media (min-width: 700px) {
  body {
    padding: 40px;
  }

  nav a {
    font-size: 1.3rem;
  }
}