:root {
  --bg-color: #ffffff;
  --text-color: #171717;
  --card-bg: #f9f9f9;
  --card-text: #171717;
}

body {
  background: var(--bg-color);
  color: var(--text-color);
  transition: background 0.3s ease, color 0.3s ease;
}

.card {
  background: var(--card-bg);
  color: var(--card-text);
  border-radius: 12px;
  transition: background 0.3s ease, color 0.3s ease;
}

/* Dark mode overrides */
body.dark-mode {
  --bg-color: #121212;
  --text-color: #e0e0e0;
  --card-bg: #1e1e1e;
  --card-text: #e0e0e0;
}

.subtitle {
  color: #666;
}
body.dark-mode .subtitle {
  color: #aaa;
}

/* Highlight user's timezone */
.card.user-zone {
  border-color: #0d6efd !important; /* Bootstrap primary */
  box-shadow: 0 0 15px rgba(13, 110, 253, 0.6);
}