body {
  font-family: 'Segoe UI', Arial, sans-serif;
  min-height: 100vh;
  margin: 0;
  padding: 0;
  background: radial-gradient(ellipse at 70% 20%, #a4508b 0%, #5f0a87 40%, #000 100%) fixed;
  position: relative;
  overflow: hidden;
}

body::before {
  content: '';
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  pointer-events: none;
  background: repeating-radial-gradient(circle at 30% 70%, rgba(255,255,255,0.08) 0, rgba(255,255,255,0.01) 40px, transparent 80px),
              repeating-radial-gradient(circle at 80% 30%, rgba(255,255,255,0.06) 0, rgba(255,255,255,0.01) 60px, transparent 120px);
  z-index: 0;
}

.card {
  border-radius: 18px;
  box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.22);
  border: none;
  background: rgba(0,0,0,0.7);
  color: #fff;
}
.card-header {
  border-top-left-radius: 18px;
  border-top-right-radius: 18px;
  font-weight: 600;
  font-size: 1.1rem;
  letter-spacing: 0.5px;
  background: linear-gradient(90deg, #8e24aa 60%, #1e88e5 100%) !important;
  color: #fff !important;
}
.card-body {
  padding: 2rem 1.5rem;
  color: #fff;
}
input[type="number"] {
  border-radius: 10px !important;
  box-shadow: 0 2px 8px rgba(31, 38, 135, 0.16);
  font-size: 1.1rem;
  background: rgba(255,255,255,0.9);
  color: #222;
  border: 1.5px solid #8e24aa;
}
.btn-success {
  font-size: 1.1rem;
  border-radius: 10px;
  font-weight: 500;
  letter-spacing: 0.5px;
  box-shadow: 0 2px 8px rgba(31, 38, 135, 0.16);
  transition: background 0.2s, color 0.2s, transform 0.2s;
  background: linear-gradient(90deg, #43cea2 0%, #185a9d 100%) !important;
  border: none;
}
.btn-success:active {
  transform: scale(0.98);
}
#ageOutput {
  min-height: 2.2rem;
  display: inline-block;
  font-weight: 600;
  letter-spacing: 0.5px;
}

pre {
  background: #f8f9fa;
  padding: 10px;
  border-radius: 8px;
}