static const char* fonts[] = { "Iosevka Nerd Font Propo:size=12" };

static const char* btnColors[]  = { "#ffffff", "#444444", "#444444" }; // fg, bg, border
static const char* dispColors[] = { "#ffffff", "#000000", "#000000" };

static const int winW = 500, winH = 500;
static const int btnW = 100, btnH = 80, gap = 10;
static const int gridX = 10, gridY = 100;

static const char* labels[4][4] = {
  {"7","8","9","/"},
  {"4","5","6","*"},
  {"1","2","3","-"},
  {"0","C","=","+"}
};