Create a three parts page layout

Question

I want to write a latex document that consists of only 1 A4 page, which is based on the article document class, and has the following layout:

Inside each "box", I need to be able to insert almost anything. Not just text, but also graphics, tikzpicture, list environment and also footnotes (there will be no floats).

How can I do that?

My approach is to create 3 minipages, as in the MWE below, and to type the content inside them.

Is this approach good? Is there a better way to achieve this page layout?

If yes, then I would like to know why I still get an Overfull \hbox warning in my code.

\documentclass[a4]{article}
\thispagestyle{empty}
\setlength\voffset{0pt}        \setlength\headsep{0pt}
\setlength\headheight{0pt}     \setlength\topmargin{0pt}
\setlength\parindent{0pt}      \setlength\marginparsep{0pt}
\setlength\marginparwidth{0pt}

\usepackage[textheight=0.9\paperheight,showframe]{geometry}

\begin{document}
\fbox{\begin{minipage}[b][2in][c]{\dimexpr\textwidth-2\fboxsep}
\center {\Huge Content that extends 100\% of the {\ttfamily textwidth}}
\end{minipage}
}%

\fbox{\begin{minipage}[t][][c]{\dimexpr 0.65\textwidth-2\fboxsep}
\center {\Huge Content that extends 65\% of the {\ttfamily textwidth}}
\end{minipage}
}%
\fbox{\begin{minipage}[t][][c]{\dimexpr 0.35\textwidth-2\fboxsep}
\center {\Huge Content that extends 35\% of the {\ttfamily textwidth}}
\end{minipage}
}
\end{document}

Answer 1

I suggest to use a tcbposter. You can define several tcbposter boxes and write whatever you want inside. In this case, there are three boxes over one column. The top box (A) and two lober boxes, B and C, whith speceific widths and being C aligned to the right. These two boxes are defined to occupy all the space between the top box and the bottom of the page. Backgorund colors are shown to easily understand the geometry.

\documentclass[a4paper]{article}
\usepackage{geometry}
\usepackage[most]{tcolorbox}
\usepackage{lipsum}

\begin{document}
\thispagestyle{empty}
\noindent\begin{tcbposter}[%
    poster = {columns=1,spacing=0pt},
    boxes = {sharp corners, boxrule=0pt}
]
\posterbox[colback=red!10]{name=A, below=top}{Some text on top
\begin{enumerate}
\item One
\item Two
\end{enumerate}}
\posterbox[colback=blue!10]{name=B, span=0.65, between=A and bottom}{\lipsum[1-2]
{\par\centering\includegraphics[width=.7\linewidth]{example-image-a}\par}}
\posterbox[colback=green!10]{name=C, column*=1, span=0.35, between=A and bottom}{\lipsum[2]
{\par\centering\begin{tikzpicture}
\node[fill=red!20, minimum size=2cm, draw=blue, thick]{A};
\end{tikzpicture}\par}}
\end{tcbposter}
\end{document}