Html body is not getting full width in tailwindcss

[theprantadutta]

Hello, I am new in tailwindcss. But I am having an issue here. What I don't understand is that I still haven't used any of the responsive classes from tailwindcss. But there are serious problems with width and I tried using tailwind class of w-full and w-screen. None of them work.
You can find the code here: https://codesandbox.io/live/95ydeco
Here's the screenshot of the problem

Thanks in Advance.