:root {
  --background-color-light: #f0f2f5;
  --text-color-light: #333;
  --container-bg-light: #fff;
  --button-bg-light: #4a90e2;
  --button-text-light: #fff;
  --lotto-ball-bg: #4a90e2;

  --background-color-dark: #2c2c2c;
  --text-color-dark: #f1f1f1;
  --container-bg-dark: #3a3a3a;
  --button-bg-dark: #5a9ee2;
  --button-text-dark: #fff;
}

body {
  font-family: 'Arial', sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
  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);
}

.container {
  text-align: center;
  background-color: var(--container-bg-light);
  padding: 40px;
  border-radius: 15px;
  box-shadow: 0 10px 20px rgba(0,0,0,0.1);
  transition: background-color 0.3s;
}

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

.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

h1 {
  margin: 0;
}

#generateBtn {
  background-color: var(--button-bg-light);
  color: var(--button-text-light);
  padding: 15px 30px;
  border: none;
  border-radius: 8px;
  font-size: 18px;
  cursor: pointer;
  transition: background-color 0.3s, transform 0.2s;
  margin-bottom: 30px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

#generateBtn:hover {
  transform: translateY(-2px);
}

body.dark-mode #generateBtn {
    background-color: var(--button-bg-dark);
    color: var(--button-text-dark);
}

.lotto-numbers {
  display: flex;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
  min-height: 60px;
}

.lotto-ball {
  width: 50px;
  height: 50px;
  display: flex;
  justify-content: center;
  align-items: center;
  border-radius: 50%;
  color: white;
  font-size: 22px;
  font-weight: bold;
  box-shadow: 0 2px 4px rgba(0,0,0,0.2);
  transition: transform 0.2s, background-color 0.5s;
  background-color: var(--lotto-ball-bg);
}

/* Dark mode toggle switch */
.switch {
  position: relative;
  display: inline-block;
  width: 50px;
  height: 28px;
}

.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: #ccc;
  transition: .4s;
  border-radius: 34px;
}

.slider:before {
  position: absolute;
  content: "";
  height: 20px;
  width: 20px;
  left: 4px;
  bottom: 4px;
  background-color: white;
  transition: .4s;
  border-radius: 50%;
}

input:checked + .slider {
  background-color: #4a90e2;
}

input:focus + .slider {
  box-shadow: 0 0 1px #4a90e2;
}

input:checked + .slider:before {
  transform: translateX(22px);
}