body {
  font-family: sans-serif;
  margin: 0;
  background-color: #f7f7f7;
  color: #333;
  transition: background-color 0.3s ease;
}

header {
  background: #111;
  color: #fff;
  padding: 2rem;
  text-align: center;
}

main {
  column-count: 3;
  column-gap: 1rem;
  padding: 1rem;
}

@media (max-width: 900px) {
  main {
    column-count: 2;
  }
}

@media (max-width: 600px) {
  main {
    column-count: 1;
  }
}

.product {
  background: #fff;
  border: 1px solid #ddd;
  padding: 1rem;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  display: inline-block;
  margin-bottom: 1rem;
  width: 100%;
  box-sizing: border-box;
  break-inside: avoid;
}

.product img {
  max-width: 100%;
  border-radius: 5px;
  display: block;
  margin-bottom: 1rem;
  object-fit: contain;
  height: auto;
  width: 100%;
}

footer {
  text-align: center;
  padding: 1rem;
  background: #222;
  color: white;
}

input[type="file"] {
  margin-top: 1rem;
  background: #fff;
  padding: 0.5rem;
  border: 1px solid #ccc;
  border-radius: 4px;
}