.upload-container {
  max-width: 400px;
  margin: 2rem auto;
  text-align: center;
  font-family: sans-serif;
}
.drop-zone {
  position: relative;
  padding: 2rem;
  border: 2px dashed #888;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.2s;
  margin-bottom: 10px;
}
.drop-zone.highlight {
  background: #f0f8ff;
}
.drop-zone p {
  margin: 0;
  color: #555;
}
#file-input {
  display: none;
}
#upload-button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}