body {
  font-family: system-ui, Arial, sans-serif;
  max-width: 900px;
  margin: auto;
  padding: 20px;
  background: #f9fafb;
  color: #111;
}

h1,
h2 {
  text-align: center;
}

.upload-area {
  border: 2px dashed #ccc;
  padding: 20px;
  text-align: center;
  border-radius: 8px;
  cursor: pointer;
  background: #fff;
  margin-bottom: 20px;
}

.upload-area.dragover {
  border-color: #007bff;
  background: #eef6ff;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin-bottom: 20px;
}

button {
  padding: 10px 15px;
  border: none;
  background: #007bff;
  color: #fff;
  border-radius: 6px;
  cursor: pointer;
}

button:disabled {
  background: #ccc;
  cursor: not-allowed;
}

.download-link {
  padding: 10px 15px;
  background: #28a745;
  color: #fff;
  border-radius: 6px;
  text-decoration: none;
}

.progress {
  font-weight: bold;
  text-align: center;
}

.output-section pre {
  background: #fff;
  border: 1px solid #ddd;
  padding: 12px;
  border-radius: 6px;
  max-height: 400px;
  overflow: auto;
}