I want to put to tcolorboxes side by side in a beamer document. I am using tcbraster to split the page in two. However, the two tcolorboxes are placed one below the other and not side by side. Strangely I manage to do what I want for the boxes "Introduction" and "Significance" but not for the "Cells" and "Demes" boxes in the attached image.
What am I doing wrong?
\documentclass{beamer}
\usepackage[size=a2,orientation=portrait,scale=1.3]{beamerposter}
\setbeamersize{text margin left=5mm,text margin right=5mm}
\RequirePackage{enumitem}
\RequirePackage[normalem]{ulem}
\RequirePackage{etoolbox}
\usepackage[skins,most]{tcolorbox}
\tcbuselibrary{skins,raster}
\usepackage{adjustbox}
\newtcolorbox{mybox}[1]{colback=white,colframe=ICOrange, coltext=ICDeepBlue, arc=3mm, title=#1}
\newtcolorbox{ghostbox}[1][]{%
colback=white,
colframe=white,
coltext=ICDeepBlue,
#1%
}
\usepackage{graphicx}
\usepackage{caption}
\graphicspath{ {./images/} }
\begin{document}
\begin{frame}[fragile=singleslide,t]\centering
\maketitle
\begin{mybox}{Introduction}
\begin{tcbraster}[raster columns=2]
\begin{ghostbox}
\begin{itemize}
\item For the principle of competitive-exclusion...
\item Plankton ...
\item Biophysical models have been recently...
\item Spatial heterogeneity...
\end{itemize}
\end{ghostbox}
\begin{mybox}{Significance: Modelling Plankton Biodiversity}
\begin{figure}
\includegraphics[width=\hsize]{significance.pdf}
\end{figure}
\end{mybox}
\end{tcbraster}
\begin{mybox}{Research Questions:}
\begin{itemize}
\item \textbf{How can microbial coexistence emerge in a resource-limited ecosystem ?}
\item \textbf{Can spatial heterogeneity in the plankton structure account for emergence of coexistence ?}
\end{itemize}
\end{mybox}
\end{mybox}
\begin{mybox}{Methods}
\begin{itemize}
\item Investigate a biophysical model and implement a computer simulation in MATLAB.
\item Assume ...
\end{itemize}
\begin{tcbraster}[raster column skip=0.1\columnwidth]
\begin{mybox}{Cells}
\begin{itemize}
\item Every species occupies point in the space of resource consumption
\end{itemize}
\begin{figure}
\includegraphics[width=\hsize]{respace.pdf}
\end{figure}
\begin{itemize}
\item Every species, $\sigma$ ...
\item To account for trade-offs...
\item Monod function: $r_i(c_i) = \frac{c_i}{k_i + c_i}$
\end{itemize}
\end{mybox}
\begin{mybox}{Demes}
\begin{figure}
\includegraphics[width=\hsize]{demes.pdf}
\end{figure}
\begin{itemize}
\item The ecosystem...
\item Nutrients...
\item Nutrients...
\end{itemize}
\end{mybox}
\end{tcbraster}
\end{mybox}
\end{frame}
\end{document}

example-imageand the undefinded colors by others. Could you please also clarify on the desired vertical alignment (top, centered...) of the two side by side boxes? In order to place the two boxes side by side, try removing the empty line between the boxes. – leandriis Apr 22 '19 at 07:59