%
% Inner theme elements, most prominently the title page
%
\ProvidesPackage{beamerinnerthemeNTNUplain}[2021/05/26 v1.0 A LaTeX beamer theme in the corporate design of NTNU]
\makeatletter
\setbeamertemplate{navigation symbols}{}%
\setbeamercolor{title}{fg=white}
\setbeamercolor{subtitle}{fg=LightGrey}
\setbeamercolor{author}{fg=white}
\setbeamercolor{date}{fg=LightGrey}
\defbeamertemplate*{title page}{NTNUplain}{%
    \begin{tikzpicture}[remember picture,overlay]% background color
        \node[at=(current page.center),fill=NTNUBlue, minimum width=\paperwidth, minimum height=\paperheight] {};%
    \end{tikzpicture}%
    \vfill%
    \centering
    \begin{beamercolorbox}[sep=8pt,center,colsep=-4bp,rounded=true,shadow=true]{institute}
        \includegraphics[width=0.7\textwidth]{\ntnu@titlelogo}
    \end{beamercolorbox}
    \vskip2.5em\par
    {\usebeamercolor[fg]{titlegraphic}\inserttitlegraphic\par}
    \begin{beamercolorbox}[sep=8pt,center,colsep=-4bp,rounded=true,shadow=true]{title}
        \usebeamerfont{title}\MakeUppercase{\inserttitle}\par%
        \ifx\insertsubtitle\@empty%
        \else%
        \vskip0.5em%
        {\usebeamerfont{subtitle}\usebeamercolor[fg]{subtitle}\insertsubtitle\par}%
        \fi%
    \end{beamercolorbox}%
    \begin{beamercolorbox}[sep=8pt,center,colsep=-4bp,rounded=true,shadow=true]{author}
        \usebeamerfont{author}\color{white}\usebeamercolor[fg]{author}\insertauthor
    \end{beamercolorbox}
    \begin{beamercolorbox}[sep=8pt,center,colsep=-4bp,rounded=true,shadow=true]{date}
        \usebeamerfont{date}\usebeamercolor[fg]{date}\insertdate
    \end{beamercolorbox}\vskip0.5em
}