:root {
  --bg-light: #f9f9f9;
  --bg-dark: #1e1e1e;
  --text-light: #333;
  --text-dark: #f9f9f9;
  --accent: #0078d7;
}

body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background-color: var(--bg-light);
  color: var(--text-light);
  transition: background-color 0.3s, color 0.3s;
}

body.dark {
  background-color: var(--bg-dark);
  color: var(--text-dark);
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
  background-color: var(--accent);
  color: white;
}

.container {
  padding: 2rem;
  max-width: 800px;
  margin: auto;
}

input, select, button {
  display: block;
  margin: 0.5rem 0;
  padding: 0.6rem;
  font-size: 1rem;
  width: 100%;
  box-sizing: border-box;
}

button {
  background-color: var(--accent);
  color: white;
  border: none;
  cursor: pointer;
  transition: transform 0.2s;
}

button:hover {
  transform: scale(1.03);
}

.controls {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 0.5rem;
  margin-top: 1rem;
}

#barcodeImage {
  display: block;
  margin: 1rem auto;
  max-width: 100%;
  height: auto;
}

#scanner {
  margin-top: 1rem;
  border: 2px dashed var(--accent);
  height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
}

.item-list {
  margin-top: 2rem;
  border-top: 1px solid #ccc;
  padding-top: 1rem;
}

footer {
  text-align: center;
  padding: 1rem;
  background-color: #eee;
  font-size: 0.9rem;
  margin-top: 2rem;
}

@media (max-width: 600px) {
  .controls {
    grid-template-columns: 1fr;
  }
}