html, body {
  margin: 0;
  padding: 0;
  overflow: hidden;
  height: 100vh;
  background: #1a1a2e;
  font-family: 'Arial', sans-serif;
  color: #fff;
}

.background {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  background: linear-gradient(125deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
}

.stars {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
}

.star {
  position: absolute;
  background: rgba(255, 255, 255, 0.5);
  border-radius: 50%;
  animation: twinkle var(--duration) ease-in-out infinite;
  opacity: 0;
}

.geometric {
  position: absolute;
  opacity: 0.15;
  border: 1px solid rgba(255, 255, 255, 0.2);
  animation: rotate var(--duration) linear infinite;
}

.circle {
  border-radius: 50%;
}

@keyframes twinkle {
  0%, 100% { opacity: 0; }
  50% { opacity: var(--intensity); }
}

@keyframes rotate {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}