Design the titlepage with tikz

\documentclass{article}[a4paper]
\usepackage{tikz}
\usetikzlibrary{calc}
\usepackage{xcolor}

\begin{document}
  \begin{titlepage}
    \centering
    \begin{tikzpicture}[remember picture,overlay]
        \node at ($(current page.north east) + (-6.2, -5.7)$) {\berkeley \HUGE \color{black} {C/C++ Curiosities}};
        \draw[fill=secondary, secondary]   (current page.south west) rectangle ($(current page.south east) + (0, 20)$);
        \draw[fill=primary, primary] ($(current page.south west) + (0, 20)$) rectangle ($(current page.south east) + (0, 21.20)$);

        \node at (3.5,-20.5) {\berkeley \Huge \color{white} {Ernesto Martínez García}};
        \node at (6.75,-21.5) {\berkeley \Large \color{white} {{EMAILDELETED}}};
        \node[draw, very thick, inner sep=8pt] at ($(current page.north west) - (-1.5, 1.5)$) {\huge \color{black} \faHashtag \berkeleybold};
  \end{tikzpicture}
...
\end{document}