For flexbox and grids u can use them both together. Flex is one dimentional and grid is 2 dimentional and both work differently. Actually there is alot of things you can do to beautify a page even as a simple form for survey forms. Youtube has plenty of examples for beautifying forms. If you feel like it you can redo again, you will see better results 
. I actually redid my survey form which i did recently. Here is mine if you want to check out, where i used both flexbox and grid