:root {
  --background-color-light: #ffffff;
  --text-color-light: #000000;
  --background-color-dark: #121212;
  --text-color-dark: #ffffff;
}

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

body.dark-mode {
  background-color: var(--background-color-dark);
  color: var(--text-color-dark);
}

#theme-toggle {
  padding: 10px 20px;
  border: 1px solid;
  border-radius: 5px;
  cursor: pointer;
}