body {
  font-family: Georgia, serif;
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 20px;
  line-height: 1.6;
  background: #ffffff;
  color: #111;
  transition: background 0.3s, color 0.3s;
}

header {
  text-align: center;
  margin-bottom: 40px;
}

nav a {
  margin: 0 10px;
  text-decoration: none;
  color: inherit;
}

nav button {
  margin-left: 10px;
  background: none;
  border: none;
  font-size: 16px;
  cursor: pointer;
}

.profile {
  display: block;
  margin: 0 auto 20px auto;
  width: 160px;
  border-radius: 50%;
}

h1 {
  text-align: center;
  margin-bottom: 5px;
}

.subtitle {
  text-align: center;
  font-style: italic;
  margin-bottom: 40px;
}

section {
  margin-bottom: 40px;
}

footer {
  text-align: center;
  margin-top: 60px;
  font-size: 14px;
  opacity: 0.7;
}

/* Dark mode */
body.dark {
  background: #111;
  color: #eee;
}

body.dark a {
  color: #9ecbff;
}

main h1, main h2, main h3 {
  margin-top: 30px;
}

main p {
  margin: 15px 0;
}

main pre {
  background: #f5f5f5;
  padding: 15px;
  overflow-x: auto;
}

body.dark main pre {
  background: #222;
}