body {
  font-family: system-ui, sans-serif;
  margin: 0;
  padding: 0;
  background-color: #f5fff8;
  color: #222;
}
nav {
  background-color: #28c25c;
  padding: 1rem;
  text-align: right;
}
nav a {
  margin-left: 1rem;
  text-decoration: none;
  color: white;
  font-weight: bold;
}
nav a:hover {
  text-decoration: underline;
}
main {
  padding: 2rem;
  max-width: 900px;
  margin: 0 auto;
}
footer {
  text-align: center;
  background-color: #28c25c;
  color: white;
  padding: 1rem;
  margin-top: 2rem;
}
h1, h2, h3 {
  color: #28c25c;
}
button.green {
  background-color: #28c25c;
  color: white;
  border: none;
  padding: 0.75rem 1.25rem;
  font-size: 1rem;
  cursor: pointer;
  border-radius: 5px;
}
button.green:hover {
  background-color: #24ad52;
}