:root {
  --bg-color: #f4f4f9;
  --text-color: #333;
  --container-bg: #ffffff;
  --button-bg: #4caf50;
  --button-hover: #45a049;
  --ball-shadow: rgba(0, 0, 0, 0.2);
}

[data-theme='dark'] {
  --bg-color: #1a1a1a;
  --text-color: #f4f4f9;
  --container-bg: #2d2d2d;
  --button-bg: #388e3c;
  --button-hover: #2e7d32;
  --ball-shadow: rgba(0, 0, 0, 0.5);
}

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

.theme-toggle {
  position: absolute;
  top: 20px;
  right: 20px;
}

#toggle-theme {
  padding: 8px 16px;
  font-size: 14px;
  cursor: pointer;
  background-color: var(--button-bg);
  color: white;
  border: none;
  border-radius: 20px;
  transition: background-color 0.3s;
}

h1 {
  margin-bottom: 30px;
}

#generate {
  padding: 12px 24px;
  font-size: 18px;
  cursor: pointer;
  background-color: var(--button-bg);
  color: white;
  border: none;
  border-radius: 8px;
  margin-bottom: 30px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  transition: background-color 0.3s, transform 0.1s;
}

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

#generate:active {
  transform: translateY(2px);
}

#numbers {
  display: flex;
  gap: 15px;
  padding: 20px;
  background-color: var(--container-bg);
  border-radius: 15px;
  box-shadow: 0 10px 20px var(--ball-shadow);
  transition: background-color 0.3s, box-shadow 0.3s;
}

.ball {
  width: 55px;
  height: 55px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  color: white;
  text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.6);
  box-shadow: 3px 3px 7px var(--ball-shadow);
  font-size: 22px;
  transition: transform 0.2s;
}

.ball:hover {
  transform: scale(1.1);
}