:root {
  --background: #ffffff;
  --text: #333333;
  --header-bg: #f0f0f0;
  --accent: #e67e22;
}

body.dark {
  --background: #1e1e1e;
  --text: #e0e0e0;
  --header-bg: #2c2c2c;
  --accent: #f39c12;
}

body {
  margin: 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--background);
  color: var(--text);
  transition: background-color 0.3s, color 0.3s;
}

.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem 1rem;
}

header {
  text-align: center;
  background-color: var(--header-bg);
  padding: 1.5rem;
  border-radius: 12px;
  margin-bottom: 2rem;
}

header h1 {
  margin: 0;
  font-size: 2rem;
  color: var(--accent);
}

header h2 {
  margin-top: 0.5rem;
  font-style: italic;
  color: gray;
  font-size: 1rem;
}

#toggle-theme {
  margin-top: 1rem;
  padding: 0.5rem 1rem;
  border: none;
  border-radius: 6px;
  background-color: var(--accent);
  color: white;
  cursor: pointer;
  font-weight: bold;
}

section {
  background-color: var(--header-bg);
  border-radius: 12px;
  padding: 1rem;
  margin-bottom: 2rem;
  text-align: center;
}

section img {
  max-width: 100%;
  height: auto;
  border-radius: 12px;
  margin: 1rem 0;
}

h3 {
  color: var(--accent);
  margin-bottom: 1rem;
}

footer {
  text-align: center;
  padding: 1rem;
  color: gray;
  font-size: 0.9rem;
}

.quiz button {
  margin: 0.5rem;
  padding: 0.5rem 1rem;
  background-color: var(--accent);
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  font-weight: bold;
}

#quiz-result {
  margin-top: 1rem;
  font-weight: bold;
}