I have a problem with changing background of the table cells/rows.

This is the code I use:

```
\documentclass{article}

\usepackage[skip=0.333\baselineskip]{caption}
\usepackage{booktabs,tabularx,ragged2e}
\usepackage{multirow}
\usepackage{graphicx}
\usepackage[table]{xcolor}

\begin{document}
\renewcommand{\arraystretch}{1.3}
\newcolumntype{Y}{>{\hsize=.7\hsize\RaggedRight\arraybackslash}X}
\newcolumntype{B}{X}

\begin{table}
\caption{Sources and targets}
\begin{tabularx}{\textwidth}{p{1cm}@{}*{4}{Y}@{}}
%% table header
\toprule
\rowcolor{lightgray}\multicolumn{2}{r@{}}{List targets} $\rightarrow$ & \multicolumn{3}{c@{}}{Targets} \\
\cmidrule(l){3-5}
\rowcolor{lightgray}\multicolumn{2}{l@{}}{\cellcolor{lightgray}$\downarrow$ Sources}  & Target 1 & Target 2 & Target 3 \\
\midrule
%% body of table
\multirow{3}{2cm}{\rotatebox{90}{\parbox{\linewidth}{sources}}} &\cellcolor{lightgray}Source 1 & Description 10 
         & Description 11 
         & Description 12 \\
\addlinespace % <-- use whitespace as a simple yet very effective divider
&\cellcolor{lightgray}Source 2 (additional info) 
         & Description 20 
         & Description 21
         & Description 22, \par
           Description 23, \par
           Description 24 \\
\addlinespace % ditto
&\cellcolor{lightgray}Source 3 & Description 30 
         & Description 31
         & Description 32, \par 
           Description 33, \par 
           Description 34 \\    
\bottomrule
\end{tabularx}
\end{table}

\end{document}

```

And the result is this:
[![enter image description here](https://i.stack.imgur.com/bqilP.png)](https://i.stack.imgur.com/bqilP.png)

Can anyone help me to make it look better? Without this white space between cells, and also this vertical column (sources) should also have the same gray background.