/* ===== Layout ===== */
body {
  font-family: "Helvetica Neue", Arial, sans-serif;
  max-width: 900px;
  margin: auto;
  padding: 20px;
  line-height: 1.6;
  background-color: #ffffffcd;
  color: #333;
  transition: background-color 0.3s, color 0.3s;
}

h1,
h2,
h3 {
  font-family: "Georgia", serif;
  color: #004080;
}

.section {
  margin-bottom: 30px;
}

#mode-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  padding: 8px 12px;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  background: #004080;
  color: #fff;
  font-weight: bold;
  transition: background 0.3s;
}

#mode-toggle:hover {
  background: #0066cc;
}