Thiệp Chúc Mừng

% Quarter-fold greeting card. Print, then fold in half twice:
% first fold the top half back, then fold left over right.
% Bottom right quadrant is the front, top quadrants are the inside
% (printed upside down so they read correctly after folding).
\documentclass{article}
\usepackage[landscape, margin=0cm, a4paper]{geometry}
\usepackage[default]{sourcesanspro}
\usepackage{xcolor}
\usepackage{tikz}
\pagestyle{empty}
\setlength{\parindent}{0pt}

\definecolor{rosepink}{HTML}{D95970}
\definecolor{sky}{HTML}{4C86B8}
\definecolor{sun}{HTML}{E8A33D}
\definecolor{leafgreen}{HTML}{5B9E6F}
\definecolor{softgray}{HTML}{9AA3AB}

\newcommand{\balloon}[4]{% x, y, color, string sway
  \fill[#3] (#1,#2) ellipse (0.55 and 0.7);
  \fill[#3!70!black] (#1,#2-0.72) -- (#1-0.09,#2-0.86) -- (#1+0.09,#2-0.86) -- cycle;
  \draw[#3!60!black, line width=0.5pt]
    (#1,#2-0.86) .. controls (#1+#4,#2-1.5) and (#1-#4,#2-2.1) .. (#1,#2-2.6);
  \fill[white, opacity=0.45] (#1-0.18,#2+0.22) ellipse (0.12 and 0.2);}

\newcommand{\confetti}[3]{\fill[#3, rotate around={35:(#1,#2)}] (#1-0.09,#2-0.03) rectangle (#1+0.09,#2+0.03);}

\begin{document}
\mbox{}% anchor for the overlay picture
\begin{tikzpicture}[remember picture, overlay, shift={(current page.center)}]
  % Fold guides.
  \draw[softgray!55, dashed, line width=0.4pt] (-14.85,0) -- (14.85,0);
  \draw[softgray!55, dashed, line width=0.4pt] (0,-10.5) -- (0,10.5);

  % ---------- Front panel: bottom right quadrant ----------
  \begin{scope}[shift={(7.42,-5.25)}]
    \draw[rosepink!45, line width=0.9pt, rounded corners=6pt]
      (-6.3,-4.35) rectangle (6.3,4.35);
    \balloon{-2.1}{1.6}{rosepink}{0.35}
    \balloon{0}{2.3}{sun}{-0.3}
    \balloon{2.1}{1.5}{sky}{0.3}
    \confetti{-3.4}{2.9}{leafgreen}
    \confetti{-4.1}{0.8}{sun}
    \confetti{3.6}{3.0}{rosepink}
    \confetti{4.3}{1.1}{sky}
    \confetti{-2.9}{-1.6}{sky}
    \confetti{3.1}{-1.3}{leafgreen}
    \node[rosepink, font=\fontsize{28}{32}\selectfont\bfseries] at (0,-1.6) {Happy Birthday!};
    \node[softgray, font=\large] at (0,-2.7) {wishing you the brightest of years};
    \draw[rosepink, line width=1pt] (-1.6,-3.35) -- (1.6,-3.35);
  \end{scope}

  % ---------- Back panel: bottom left quadrant ----------
  \begin{scope}[shift={(-7.42,-5.25)}]
    \node[softgray, font=\scriptsize] at (0,-3.7) {made with care, from our kitchen table to yours};
    \fill[rosepink] (0,-3.1) circle (0.06);
  \end{scope}

  % ---------- Inside right: top left quadrant, rotated 180 ----------
  \begin{scope}[shift={(-7.42,5.25)}, rotate=180, every node/.append style={rotate=180}]
    \node[align=center, text width=9.5cm, font=\large] at (0,0.6)
      {Another year of stories, laughter,\\
       and cake eaten straight from the tin.\\[1.2em]
       May this one bring you everything\\
       you have been quietly hoping for.};
    \node[rosepink, font=\Large\bfseries] at (0,-2.4) {With love, the Hartley family};
    \confetti{-3.9}{2.6}{sun}
    \confetti{3.9}{2.5}{sky}
  \end{scope}

  % ---------- Inside left: top right quadrant, rotated 180 ----------
  \begin{scope}[shift={(7.42,5.25)}, rotate=180, every node/.append style={rotate=180}]
    \balloon{0}{1.0}{leafgreen}{0.3}
    \node[softgray, font=\small\itshape] at (0,-2.2) {sixty candles and counting};
  \end{scope}
\end{tikzpicture}
\end{document}