How can I have the size of a mindmap node be calculated automatically by TikZ such that the text inside fits nicely inside? With inner sep=... I am able to have the height fit in such a way, but not the width. Btw.: I am using rectangles as nodes, not the standard circles.
\documentclass[tikz,border=5]{standalone}
\usetikzlibrary{mindmap}
\tikzset{
every node/.append style={concept, rectangle, minimum size=0cm, inner sep=2mm}
}
\begin{document}
\begin{tikzpicture}[mindmap,text=white]
\node {O} child { node {A} };
\end{tikzpicture}
\end{document}
