在 verbatim 环境中生根

Question

首先：这是一个类似于这里并且（希望）这是我最后一个此类问题。

如何在绿色框中输入像素化的 n 次方根符号，并在其“下方”输入数字？即输出的像素化版本，例如$\sqrt[4]{81}$。

如果在括号内的等价内容中没有写任何内容，那么$\sqrt[4]{81}$它应该会产生一个平方根（当然也是像素化的）。

\documentclass[
  a4paper,
  12pt
]{article}

\usepackage[varg]{newpxmath}
\usepackage[
  hmargin = 2.4cm,
  vmargin = 3cm
]{geometry}

\usepackage[most]{tcolorbox}
  \colorlet{blackened}{black!90!white}
  \colorlet{blackish}{black!70!white}
  \colorlet{greyish}{black!60!white}
  \colorlet{lightgreyish}{black!10!white}
  \colorlet{whiteish}{white}
  \colorlet{orangeish}{yellow!90!red}
  \colorlet{greenish}{green!16!gray}
  \colorlet{redish}{red!80!black}

\tcbset{
  calbackground/.style = {
    enhanced,
    leftright skip = 0.15cm,
    beforeafter skip = 0pt,
    toptitle = 0mm,
    bottomtitle = 0mm,
    right = 3pt,
    left = 3pt,
    top = 4pt,
    bottom = 4pt,
    boxsep = 0pt,
    boxrule = 0mm,
    sharp corners,
    sidebyside,
    sidebyside gap = 6pt,
    lefthand ratio = 0.61,
    bicolor,
    colback = lightgreyish,
    colbacklower = greenish,
    colframe = white,
    autoparskip,
  }
}

\newtcbtheorem[no counter]{calx}{Calculator}{calbackground}{cax}

\newtcbox{\KY}[1][]{
  enhanced,
  on line,
  arc = 2pt,
  outer arc = 2pt,
  boxrule = 0pt,
  bottomrule = 0.15mm,
  rightrule = 0.2mm,
  boxsep = 0pt,
  left = 0pt,
  right = 0pt,
  top = 1pt,
  bottom = 1pt,
  interior style = {
    top color = blackish,
    bottom color = blackened
  },
  colframe = greyish,
  width = 2.5em,
  tcbox width = forced center,
  equal height group = K,
  valign = center,
  fontupper = \footnotesize\sffamily,
  coltext = orangeish,
  before upper = \vrule width 0pt height 2ex depth 1ex\relax,
}

\newtcbox{\KYm}[1][]{
    enhanced,
    on line,
    arc = 2pt,
    outer arc = 2pt,
    boxrule = 0pt,
    bottomrule = 0.25mm,
    rightrule = 0.2mm,
    boxsep = 0pt,
    left = 0pt,
    right = 0 pt,
    top = 1pt,
    bottom = 1pt,
    interior style = {
      top color = blackish,
      bottom color = blackened
    },
    colframe = greyish,
    width = 2.5em,
    tcbox width = forced center,
    equal height group = K,
    valign = center,
    fontupper = \footnotesize\sffamily,
    coltext = orangeish,
    before upper = \vrule width 0pt height 2ex depth 1ex\relax$,
    after upper = $,
    }

\newtcbox{\KN}{
  enhanced,
  on line,
  arc = 2pt, outer arc = 2pt,
  boxrule = 0pt,
  bottomrule = 0.15mm,
  rightrule = 0.2mm,
  boxsep = 0pt,
  left = 0pt,
  right = 0pt,
  top = 1pt,
  bottom = 1pt,
  interior style = {
    top color = blackish,
    bottom color = blackened
  },
  colframe = greyish,
  width = 2.5em,
  tcbox width = forced center,
  equal height group = K,
  valign = center,
  fontupper = \footnotesize\sffamily,
  coltext = whiteish,
  before upper = \vrule width 0pt height 2ex depth 1ex\relax,
}

\usepackage{lcd}
  \LCDcolors{black}{greenish}
  \DefineLCDchar{sq}{11100001000100011100000000000000000}
  \DefineLCDchar{tm}{00000100010101000100010101000100000}
  \DefineLCDchar{dv}{00000001000000011111000000010000000}
  \DefineLCDchar{mu}{00011000011110100001000000000000000}
  \DefineLCDchar{sc}{11011010011001000000000000000000000}

\usepackage{MnSymbol}
\usepackage{xfrac}

\begin{document}

\begin{calx}{}{}
  \KN{4}
  \KY{2nd}
  \KYm{\wedge}
  \KN{8}
  \KN{1}
  \KYm{\smalltriangleright}
  \KY{enter}
  \tcblower
  {\Large
   \vspace*{-0.5ex} 
   \textLCD[0]{16}||
   \textLCD[0]{15}|               3|}
\end{calx}

\end{document}