Intro section with dropdown navigation - Flexbox

Hi, this is my solution for Intro section with dropdown navigation, feel free to write feedback about my dropdown navigation.

I'm not sure whether there is too much "chaos" on desktop devices, as mobile design was my priority (according to mobile-first idea).

I'm also not sure if my whole website calibrate correctly when I widen it in dev tools, from mobile moving to tablet and ending at desktop.

Waiting for advice what I could have done better (except everything :)).

PS. sorry for bad english!