Survey form feedback would be awesome

Project on codepen. Any feedback is appreciated!

I tried not to overinvest time in it, my approach to learning is more about moving on (currently I’m in JS course), but look back on projects regularly.

I have some questions:

About text and input alignment inside label elements(CSS file has comment in relevant part of code).

<label>some text <input></input></label>

I saw implementation of such cases with flexbox in freeCode Camp Survey form example:

label  {
     display: flex;
     align-items: center;

But i there is also approach (in part of curriculum learn HTML forms building registration form):

input {
      vertical-align: middle;

I chose the second one but ended up adjusting vertical-align property with percentage values, because with vertical-align set to middle text and input wasn’t on one level at all and I’m not sure why.

About rem and em. I found it convinient to use rem setting font-size, but I don’t think I understand logic when choosing between em and rem in other instances. In this project i made such decisions based on what I saw in curriculum challenges.