Instead of .side / .main horizontally, flex vertically with .header / .main so that settings and live-text get automatically aligned (as in, same baseline). Within each horizontally flex-grown area, divide space in two with the left space having a fixed width.
Instead of .side / .main horizontally, flex vertically with .header / .main so that settings and live-text get automatically aligned (as in, same baseline). Within each horizontally flex-grown area, divide space in two with the left space having a fixed width.