:root {
  --background-color: #f0f0f0;
  --container-background: white;
  --text-color: #000;
  --button-background: #4CAF50;
  --button-hover-background: #45a049;
  --number-background: #f0f0f0;
}

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

body.dark-mode {
  --background-color: #121212;
  --container-background: #1e1e1e;
  --text-color: #fff;
  --button-background: #4a4a4a;
  --button-hover-background: #5a5a5a;
  --number-background: #333;
}

.container {
  text-align: center;
  background-color: var(--container-background);
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  position: relative;
}

h1 {
  margin-bottom: 1.5rem;
}

button {
  background-color: var(--button-background);
  color: white;
  border: none;
  padding: 10px 20px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
  margin: 4px 2px;
  cursor: pointer;
  border-radius: 5px;
  transition: background-color 0.3s;
}

button:hover {
  background-color: var(--button-hover-background);
}

.numbers-container {
  display: flex;
  justify-content: center;
  margin-top: 1.5rem;
}

.number {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 40px;
  height: 40px;
  background-color: var(--number-background);
  border-radius: 50%;
  margin: 0 5px;
  font-size: 1.2rem;
  font-weight: bold;
}

.theme-switch-wrapper {
  position: absolute;
  top: 10px;
  right: 10px;
}

.theme-switch {
  display: inline-block;
  height: 34px;
  position: relative;
  width: 60px;
}

.theme-switch input {
  display:none;
}

.slider {
  background-color: #ccc;
  bottom: 0;
  cursor: pointer;
  left: 0;
  position: absolute;
  right: 0;
  top: 0;
  transition: .4s;
}

.slider:before {
  background-color: #fff;
  bottom: 4px;
  content: "";
  height: 26px;
  left: 4px;
  position: absolute;
  transition: .4s;
  width: 26px;
}

input:checked + .slider {
  background-color: #2196F3;
}

input:checked + .slider:before {
  transform: translateX(26px);
}

.slider.round {
  border-radius: 34px;
}

.slider.round:before {
  border-radius: 50%;
}