I would like to following picture in tikz, for which I have written the code. However scaling this image, distorts the location of the rectangle nodes. In my picture shown, there are common edges between the nodes. Irrespective of scaling, I don't want them to be distorted. Could someone give me tips to resolve this problem?
\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\node (rxst0) at (0.75,-0.5) [draw,fill=gray!20,minimum height=0.65cm,minimum width=0.5cm] {$st_0$};
\node (rxst1) at (2.25,-0.5) [draw,fill=gray!20,minimum height=0.65cm,minimum width=0.5cm] {$st_1$};
\node (c0pos0) at (0,0) [draw,minimum height=0.65cm,minimum width=1.0cm] {$pos_0$};
\node (c0st0) at (0.75,0) [draw,fill=gray,minimum height=0.65cm,minimum width=0.5cm] {$st_0$};
\node (c0pos1) at (1.55,0) [draw,minimum height=0.65cm,minimum width=1.0cm] {$pos_1$};
\node (c0st1) at (2.25,0) [draw,fill=gray,minimum height=0.65cm,minimum width=0.5cm] {$st_1$};
\end{tikzpicture}
\end{document}
Here is how the distorted image looks like -
I also tried something like following, but it doesn't work.
\node (c0st0) [anchor=west,right of=c0pos0,node distance=0cm,draw,fill=gray,minimum height=0.65cm,minimum width=0.5cm] {$st_0$};
Thank You
positioning
tikzlibrary