How can I align the nodes of the following tikz organigram?
\documentclass[10pt,letterpaper]{article}
\usepackage[margin=0.5cm, hmargin=0.5cm,vmargin=0.5cm]{geometry}
\usepackage{tikz}
\usepackage{pgfplots}
\usetikzlibrary{trees}
\begin{document}
\begin{center}
\begin{tikzpicture}[auto, node distance = 1cm, thick,
every node/.style = {rectangle, font = \sffamily, white,
top color = blue!90!black, bottom color = blue!60!black,
text width = 3.5cm, align = center, minimum height = 1cm}]
\node (MAN) {\textbf{Adam Smith}\\CEO};
\node (PROD) [below left = 5cm of MAN] {\textbf{John Doe}};
\node (FIN) [below = 3cm of MAN] {\textbf{Steve Sanders}};
\node (RRHH) [below right = 5cm of MAN] {\textbf{Mike Donovan}};
\draw [blue,thick]
(MAN) -- (FIN)
(MAN) -| (PROD)
(MAN) -| (RRHH);
\end{tikzpicture}
\end{center}
\end{document}
I tried to modify the node distance and the node position but they never align properly, the position is never at the same level and the separation between the levels and the nodes is very wide.
Thanks in advance for your time!