:root {
  --background-color: #f4f4f9;
  --text-color: #2c3e50;
  --button-gradient-start: #667eea;
  --button-gradient-end: #764ba2;
  --button-text-color: white;
  --lotto-set-bg: #ffffff;
  --lotto-set-shadow: rgba(0, 0, 0, 0.05);
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  margin: 0;
  padding: 20px;
  background-color: var(--background-color);
  color: var(--text-color);
  transition: background-color 0.3s, color 0.3s;
}

body.dark-mode {
  --background-color: #2c3e50;
  --text-color: #f4f4f9;
  --button-gradient-start: #764ba2;
  --button-gradient-end: #667eea;
  --lotto-set-bg: #34495e;
  --lotto-set-shadow: rgba(0, 0, 0, 0.2);
}

h1 {
  color: var(--text-color);
  margin-bottom: 30px;
  font-weight: 600;
}

#lotto-sets-container {
  display: flex;
  flex-direction: column;
  gap: 20px;
  width: 100%;
  max-width: 600px;
  margin-bottom: 30px;
}

.lotto-set {
  background: var(--lotto-set-bg);
  padding: 15px;
  border-radius: 10px;
  box-shadow: 0 2px 10px var(--lotto-set-shadow);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.lotto-container {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.bonus-display {
    display: flex;
    align-items: center;
    gap: 10px;
}

.plus-sign {
    font-size: 24px;
    font-weight: bold;
    color: var(--text-color);
}

#generate-btn, #theme-toggle {
  padding: 12px 30px;
  font-size: 18px;
  font-weight: 500;
  border: none;
  border-radius: 25px;
  background: linear-gradient(135deg, var(--button-gradient-start) 0%, var(--button-gradient-end) 100%);
  color: var(--button-text-color);
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
  transition: transform 0.2s, box-shadow 0.2s;
  margin: 0 10px;
}

#generate-btn:hover, #theme-toggle:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.25);
}

#generate-btn:active, #theme-toggle:active {
  transform: translateY(0);
}