\mode<presentation>

\setbeamertemplate{background}{
  \begin{tikzpicture}
    \ifnum\thepage>1\relax%
    \begin{beamercolorbox}{tuhh teal}
      \useasboundingbox (0,0) rectangle(\the\paperwidth,\the\paperheight);
      \node[outer sep=0, inner sep=0] (tuhh_logo) at (309.42mm+7.91mm, \the\paperheight-26.05mm) {\includegraphics[width=25.82mm]{.theme_imgs/TUHH_logo_rgb.pdf}};
      \useasboundingbox (0,0) rectangle(\the\paperwidth,\the\paperheight);
      %date
       \node[rectangle,
        minimum width = 30.76 mm,
        minimum height = 4.97 mm,
        outer sep = 0mm,
        inner sep = 0.0mm,
        anchor = west,
        ] at (301.7 mm, \the\paperheight-181.27 mm) {\usebeamerfont{date_small} \insertdate};
      %slide number
      \node[rectangle,
        minimum width = 16.12mm,
        minimum height = 4.0mm,
        outer sep = 0mm,
        inner sep = 0.0mm,
        anchor = west,
        ] at (309.0mm, \the\paperheight-135.26mm) {\usebeamerfont{frame_number} \insertframenumber};

      \useasboundingbox (0,0) rectangle(\the\paperwidth,\the\paperheight);
        \node[rectangle,
              draw,
              line width = 1pt,
              minimum width = 327.91mm,
              minimum height = 179.99mm,
              outer sep = 5.34mm,
              anchor = south west,
              ] at (0, 0) {};

        %upper horz 1
        \draw (5.33mm, \the\paperheight-37.26mm) -- (5.33mm+295.89mm,\the\paperheight-37.26mm) {};
        %upper horz 2
        \draw (301.22mm, \the\paperheight-37.25mm) -- (301.22mm+32.10mm, \the\paperheight-37.25mm) {};
        %mid horz 1
        \draw (301.22mm, \the\paperheight-95.25mm) -- (301.22mm+32.10mm, \the\paperheight-95.25mm) {};
        %lower horz 1
        \draw (301.22mm, \the\paperheight-169.25 mm) -- (301.22mm+32.10mm, \the\paperheight-169.25 mm) {};
        %first vert
        \draw (301.22mm, \the\paperheight-5.24mm) -- (301.22mm, \the\paperheight-5.24mm-180.00mm) {};
      \end{beamercolorbox}%
    \fi

    % First page is always landing page
    \ifnum\thepage<2\relax%
      % TUHH Logo
      \node[outer sep=0, inner sep=0] (tuhh_logo) at (19.07mm+25.875mm, \the\paperheight-109.93mm-18.923mm) {\includegraphics[width=73.75mm]{.theme_imgs/TUHH_logo-wortmarke_en_rgb.pdf}};
      % TUHH Building A
      \node[outer sep=0, inner sep=0pt] at (178.816mm+72.75mm, \the\paperheight-104.902mm-23.177mm) {\includegraphics[width=148.59mm]{.theme_imgs/TUHH_building-a.png}};

      \useasboundingbox (0,0) rectangle(\the\paperwidth,\the\paperheight);
      \begin{beamercolorbox}{tuhh teal}
        \node[rectangle,
              draw,
              line width = 1pt,
              minimum width = 327.91mm,
              minimum height = 179.99mm,
              outer sep = 5.34mm,
              anchor = south west,
              ] at (0, 0) {};

        \draw (169.25mm, \the\paperheight-5.24mm) -- (169.25mm, \the\paperheight-5.24mm-180.00mm) {};
        \draw (5.33mm, \the\paperheight-95.25mm) -- (5.33mm+328.00mm, \the\paperheight-95.25mm) {};
        \draw (5.33mm, \the\paperheight-160.51mm) -- (5.33mm+328.00mm, \the\paperheight-160.51mm) {};
        \draw (87.31mm, \the\paperheight-95.25mm) -- (87.31mm, \the\paperheight-95.25mm-65.26mm) {};
        \draw (87.31mm, \the\paperheight-142.52mm) -- (87.31mm+81.93 mm, \the\paperheight-142.52mm) {};
        \draw (87.31mm, \the\paperheight-118.80mm) -- (87.31mm+81.93 mm, \the\paperheight-118.80mm) {};
        \draw (128.27mm, \the\paperheight-95.25mm) -- (128.27mm, \the\paperheight-95.25mm-47.27mm) {};

        % First triangle
        \draw (87.31mm, \the\paperheight-95.07mm) -- (87.31mm+40.96mm, \the\paperheight-95.07mm-23.72mm) {};
        \draw (128.27mm, \the\paperheight-95.07mm-23.72mm) -- (128.27mm+40.96mm, \the\paperheight-95.07mm) {};

        % Second triangle
        \draw (87.31mm, \the\paperheight-118.80mm) -- (87.31mm+40.96mm, \the\paperheight-118.80mm-23.72mm) {};
        \draw (128.27mm, \the\paperheight-118.80mm-23.72mm) -- (128.27mm+40.96mm, \the\paperheight-118.80mm) {};

        % First Red Circle
        \draw[red,fill=red] (126.96mm+1.325mm, \the\paperheight-93.93mm-1.325mm) circle (1.325mm);
        % Second Red Circle
        \draw[red,fill=red] (126.96mm+1.325mm, \the\paperheight-117.48mm-1.325mm) circle (1.325mm);
        % Third Red Circle
        \draw[red,fill=red] (126.96mm+1.325mm, \the\paperheight-141.20mm-1.325mm) circle (1.325mm);
      \end{beamercolorbox}%
      \fi
  \end{tikzpicture}
}

% Title page
\defbeamertemplate*{title page}{tuhh}[1][]
{ 
    \begin{beamercolorbox}[leftskip=0mm,wd=142.19mm,dp=66.32mm,ht=66.30mm,#1]{title page header}
      \usebeamerfont{title}\inserttitle%
    \end{beamercolorbox}%
    \begin{beamercolorbox}[wd=1mm,ht=14mm,#1]{title page header}
      % Margin Placeholder
    \end{beamercolorbox}%
    \begin{beamercolorbox}[leftskip=114.285mm,wd=550mm,#1]{title page header}
      \usebeamerfont{date}\DTMsetdatestyle{ddmmyyyy}\insertdate
    \end{beamercolorbox}%
    \begin{beamercolorbox}[wd=1mm,ht=12mm,#1]{title page header}
      % Margin Placeholder
    \end{beamercolorbox}%
    \begin{beamercolorbox}[leftskip=21.336mm,wd=550mm,#1]{title page header}
      \usebeamerfont{author}\insertauthor
    \end{beamercolorbox}%
}

\mode
<all>