body {
  font-family: sans-serif;
  background: #f0f0f0;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 30px;
}

h1 {
  margin-bottom: 20px;
  text-align: center;
}

#container {
  background: #fff;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 3px 10px rgba(0,0,0,0.15);
  width: 100%;
  max-width: 600px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 15px;
}

input[type="file"] {
  margin-bottom: 10px;
}

button {
  padding: 10px;
  font-size: 16px;
  border-radius: 8px;
  border: none;
  background-color: #4CAF50;
  color: white;
  cursor: pointer;
}

button:hover {
  background-color: #45a049;
}

.preview {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 10px;
  justify-content: center;
}

.preview canvas {
  border: 1px solid #ccc;
  border-radius: 4px;
  width: 100px;
  height: auto;
}