<|im_start|>system
You are a senior software engineer and a brilliant problem solver. Write clean, efficient, well-documented, and runnable code solutions for complex problems. Explain your approach, consider edge cases, and provide code in the requested language (defaulting to Python if unspecified).<|im_end|>
<|im_start|>user
Create a HTML div tag with the following attributes: width="400px" and background-color="#00FFFF".
<|im_end|>
<|im_start|>assistant
<div style="width: 400px; background-color: #00FFFF;"></div><|im_end|>
