@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600&display=swap');

:root {
  --bg: #ffffff;
  --text: #1f2937;
  --accent: #2563eb;
  --header-bg: #f3f4f6;
  --card-bg: #ffffff;
  --border: #d1d5db;
}
body.dark {
  --bg: #111827;
  --text: #f3f4f6;
  --accent: #facc15;
  --header-bg: #1f2937;
  --card-bg: #1e293b;
  --border: #374151;
}
body {
  margin: 0;
  padding: 0;
  font-family: 'Inter', sans-serif;
  background-color: var(--bg);
  color: var(--text);
  transition: background-color 0.3s, color 0.3s;
}
header {
  background-color: var(--header-bg);
  padding: 1rem;
  text-align: center;
  border-bottom: 1px solid var(--border);
}
header h1 {
  margin: 0.5rem 0;
  font-size: 2rem;
  color: var(--accent);
}
header h2 {
  margin: 0.25rem 0;
  font-weight: normal;
}
main {
  max-width: 800px;
  margin: 2rem auto;
  padding: 0 1rem;
  animation: fadeIn 0.6s ease-in;
}
section {
  background-color: var(--card-bg);
  padding: 1rem;
  border-radius: 8px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
  margin-bottom: 1.5rem;
  border: 1px solid var(--border);
  transition: background-color 0.3s, border 0.3s;
}
section h3 {
  border-bottom: 2px solid var(--accent);
  padding-bottom: 0.5rem;
  margin-bottom: 1rem;
}
ul {
  list-style-type: disc;
  padding-left: 1.5rem;
}
footer {
  text-align: center;
  padding: 2rem;
  font-size: 0.9rem;
  color: var(--text);
}
nav a {
  margin: 0 0.5rem;
  text-decoration: none;
  color: var(--accent);
}
nav a:hover {
  text-decoration: underline;
}
button {
  margin-top: 1rem;
  background: var(--accent);
  color: white;
  padding: 0.5rem 1rem;
  border: none;
  cursor: pointer;
  border-radius: 4px;
  font-size: 1rem;
}
button:hover {
  background: #1e40af;
}

@keyframes fadeIn {
  0% { opacity: 0; transform: translateY(10px); }
  100% { opacity: 1; transform: translateY(0); }
}

/* Responsive styles */
@media (max-width: 600px) {
  header h1 {
    font-size: 1.5rem;
  }
  main {
    padding: 1rem;
  }
  section {
    padding: 0.75rem;
  }
  button {
    width: 100%;
  }
}