매우 정성을 들여 꼼꼼하고 철저하게.
In a way that shows great care, thoroughness, and extreme attention to detail.
예문:
"The ancient manuscript was painstakingly transcribed by hand over several years."
"She painstakingly researched every detail of the historical event before writing her novel."
"The detective painstakingly examined the crime scene for any overlooked evidence."