Modify multicol environment based on content

Question

When having the following MWE:

\documentclass[10pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{makeidx}
\usepackage{blindtext}
\usepackage{graphicx}
\usepackage{multicol}
\begin{document}
    \begin{multicols}{2}
        \begin{minipage}{0.9\linewidth}
            \blindtext
        \end{minipage}

        \begin{minipage}{0.9\linewidth}
            \blindtext
        \end{minipage}

        \begin{minipage}{0.9\linewidth}
            \blindtext
        \end{minipage}
    \end{multicols}
\end{document}

my last minipage will end up as a left column. Is there a possibility to detect if the right column is empty, and if yes, to center the last minipage?

Answer 1

You can use a tcbraster environment with the last box centered.

\documentclass[10pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{makeidx}
\usepackage{lipsum}
\usepackage{graphicx}
%\usepackage{multicol}
\usepackage[most]{tcolorbox}
\begin{document}
    \begin{tcbraster}[blankest, raster columns=2, raster equal height, raster halign=center, raster column skip=5mm, raster row skip=5mm]
        \begin{tcolorbox}
            \lipsum[2]
        \end{tcolorbox}
        \begin{tcolorbox}
            \lipsum[2]
        \end{tcolorbox}
        \begin{tcolorbox}
            \lipsum[2]
        \end{tcolorbox}
    \end{tcbraster}
\end{document}