如何让顶部节点居中？

Question

我在微调图片时遇到了问题。图片几乎是应有的样子，但“节点 a”并没有真正居中，因为它太靠右了，其余部分太靠下了。你能帮忙吗？

我使用的代码是：

\begin{figure}[h]
    \centering
    \begin{tikzpicture}
        % Coordinate for centering 'a'
        \coordinate (center) at (0,0);

        % Texts without boxes
        \node[](a) at (center) {\textbf{Exploitation of the error of rationality}};
        \node[below left=1.5cm and -1.5cm of a, align=center] (b) {Motivated Influence};
        \node[below right=1.5cm and -2.75cm of a, align=center] (c) {Cognitive disability};

        % Boxes
        \node[draw, below=0.15cm of b.south, text width=6.3cm, align=center] (d)  {\textbf{Psyops Domain}
            \linebreak
            \linebreak Action on beliefs
            \linebreak Distorted perceptions
            \linebreak Cultural illusion
            \linebreak Anxiety and fears
            \linebreak Personality weaknesses and strengths
            \linebreak Repression};
        \node[draw, right=0.5cm of d, text width=6.3cm, align=center] (e) {\textbf{Cognitive Warfare Domain}
            \linebreak
            \linebreak Action on cognitions
            \linebreak Sensory and perceptive overflow
            \linebreak Attentional saturation
            \linebreak Tunneling of attention
            \linebreak Errors of judgment
            \linebreak Cognitive biases};

        % Arrows
        \draw[-stealth] (a) -- (b);
        \draw[-stealth] (a) -- (c);
    \end{tikzpicture}
    \caption{Differences Between Cognitive Warfare and PSYOPS (Including, in Broad Terms, Actual Psychological Operations and Other Non-Kinetic Actions such as Influence Operations and Civil-Military Cooperation)}
    \label{fig:figexplot}
\end{figure}