:root {
  --bg-color: #f0f0f0;
  --container-bg: transparent;
  --text-color: #333;
  --number-bg: #fff;
  --number-border: #ccc;
  --btn-bg: #efefef;
  --btn-text: #000;
}

[data-theme="dark"] {
  --bg-color: #121212;
  --container-bg: #1e1e1e;
  --text-color: #e0e0e0;
  --number-bg: #333;
  --number-border: #555;
  --btn-bg: #333;
  --btn-text: #fff;
}

body {
  font-family: sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background-color: var(--bg-color);
  color: var(--text-color);
  transition: background-color 0.3s, color 0.3s;
}

.container {
  text-align: center;
  padding: 20px;
  background-color: var(--container-bg);
  border-radius: 8px;
}

.numbers-container {
  display: flex;
  margin-bottom: 20px;
  justify-content: center;
}

.number {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background-color: var(--number-bg);
  border: 2px solid var(--number-border);
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 24px;
  margin: 0 5px;
  transition: background-color 0.3s, border-color 0.3s;
}

#generate-btn {
  padding: 10px 20px;
  font-size: 18px;
  cursor: pointer;
  background-color: var(--btn-bg);
  color: var(--btn-text);
  border: 1px solid var(--number-border);
  border-radius: 4px;
  transition: background-color 0.3s, color 0.3s;
}

#theme-toggle {
  position: absolute;
  top: 20px;
  right: 20px;
  padding: 8px 16px;
  cursor: pointer;
  background-color: var(--btn-bg);
  color: var(--btn-text);
  border: 1px solid var(--number-border);
  border-radius: 4px;
  transition: background-color 0.3s, color 0.3s;
}