\DocumentMetadata{tagging=on}
\documentclass{article}

\usepackage[a4paper,margin=28mm]{geometry}
\usepackage{osgstyler-lua}
\usepackage{tagdirtree}

% Same tree-building macros (\dtdir/\dtfile/\dtarchive) and the same
% accessible tagging as the default tagdirtree skin -- nothing here
% touches semantics. Only the *appearance* changes: connector lines
% instead of icons, colored from an osgstyler theme instead of fixed
% black. Compare with a plain \usepackage{tagdirtree} document to see
% that the /Alt text and structure in the PDF stay identical either way.

\DeclareOsgColorPalette{editorial}{
  primary   = {model=RGB, value={36,74,115}},
  accent    = {model=RGB, value={217,119,6}},
  structure = {alias=primary}
}
\UseOsgColorPalette{editorial}

% \dtdir/\dtfile/\dtarchive still call \tagdirtreeconnector for every
% entry, artifact-wrapped -- the base package's default is empty
% (\tagdirtreedepth is tracked either way). \tagdirtreedepth is a plain
% counter of surrounding directories, not a position within the
% sibling list, so this cannot distinguish the true last entry at a
% level (no "+--" vs a closing corner) without look-ahead across the
% enclosing \dtdir's argument -- every branch uses the same connector.
\setlist[itemize]{label=,leftmargin=1.2em,itemindent=0pt}
\ExplSyntaxOn
\RenewDocumentCommand \tagdirtreeconnector { }
  {
    \int_compare:nNnT { \tagdirtreedepth } > { 0 }
      {
        \textcolor{\OsgColorName{accent}}{%
          \int_step_inline:nn { \tagdirtreedepth - 1 } { |~~ }
          +\/-~
        }%
      }
  }
\ExplSyntaxOff

% Icons stay on (default placeholders); a skin can drop them just as
% easily by redefining \tagdirtree{file,directory,archive}icon to
% produce nothing.

\begin{document}

\section*{tagdirtree: a connector-line skin}

The tree below uses the same \verb|\dtdir|/\verb|\dtfile|/\verb|\dtarchive|
calls as any other \texttt{tagdirtree} document -- only
\verb|\tagdirtreeconnector| was redefined, plus an \texttt{osgstyler} color
palette for the connector's color.

\begin{tagdirtree}
  \dtdir{project}{root directory}{
    \dtdir{src}{source code}{
      \dtfile{main.py}{entry point}
      \dtfile{util.py}{}
    }
    \dtfile{README.md}{documentation}
    \dtarchive{legacy.zip}{old sources}
  }
\end{tagdirtree}

\end{document}