Please give me your feedback for my projects “Survey Form” “A Tribute Page”

Survey Form:
I would recommend that make it mobile friendly. It should not leave any space left and right on small width device. instead of width : 70%, use max–width : 768px; (or any fix width you like)

I would recommend using flex-box to center the element. it wil be lot less code.

Beauty of Nature :
When I reduce the browser size, I see the horizontal sccrollbar and I had to scroll left and right to read lines. You should make it mobile responsive.
You have define height and width of image :

width: 1000px;
 height: 800px;`

That’s why image is still bigger on big device. Also you have set width on #thin container to be exact 700px; Change all those width to max-width.
Also I see that on Img you applied width : 100% and than you applied max-width : 840px; It don’t work like that. when you said width to be 100% it will be 100% and regardless of what max-width you apply. So, you should use width or max-width only.