body { font-family: Arial, sans-serif; padding: 20px; }
.aside { position: fixed; left: -220px; top: 0; width: 200px; height: 100%; background: #f2f2f2; padding: 10px; transition: 0.2s; }
.aside.active { left: 0; }
.main { margin-top: 20px; }
#barcode-input { padding: 8px; width: 260px; }
.btn { padding: 8px 12px; margin-left: 6px; cursor: pointer; }
#result { margin-top: 12px; font-weight: bold; }