:root {
  --background-color: #f0f0f0;
  --container-bg: #fff;
  --text-color: #333;
  --button-bg: #007bff;
  --button-hover-bg: #0056b3;
  --lotto-number-bg: #4caf50;
  --lotto-number-color: #fff;
}

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: #1a1a1a;
  --container-bg: #2c2c2c;
  --text-color: #f0f0f0;
  --button-bg: #0056b3;
  --button-hover-bg: #007bff;
  --lotto-number-bg: #5a9a5d;
}

.container {
  text-align: center;
  background-color: var(--container-bg);
  padding: 2rem;
  border-radius: 10px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
  transition: background-color 0.3s;
}

h1 {
  color: var(--text-color);
}

.lotto-numbers {
  display: flex;
  justify-content: center;
  margin: 1.5rem 0;
}

.lotto-number {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: var(--lotto-number-bg);
  color: var(--lotto-number-color);
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 0 0.5rem;
  font-size: 1.2rem;
  font-weight: bold;
}

#generate-btn {
  background-color: var(--button-bg);
  color: #fff;
  border: none;
  padding: 0.8rem 1.5rem;
  border-radius: 5px;
  cursor: pointer;
  font-size: 1rem;
  transition: background-color 0.3s;
}

#generate-btn:hover {
  background-color: var(--button-hover-bg);
}

#theme-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background-color: var(--button-bg);
    color: #fff;
    border: none;
    padding: 0.5rem;
    border-radius: 5px;
    cursor: pointer;
}