I have this code:
\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{mindmap}
\begin{document}
\begin{tikzpicture}[text width=2.7cm,
align=flush center,
grow cyclic,
level 1/.style={level distance=5cm,sibling angle=180},
level 2/.style={level distance=3cm,sibling angle=45}
]
\node{28 Days Later (2003)}
child { node {Ancestors} }
child { node {Night of the Living Dead (1968) } }
child { node {The Omega Man (1970) } }
child { node {The Day of the Triffids (1959) } }
child { node {I Am Legend (1954) } }
child { node {The War of the Worlds (1894) } }
child { node {Descendants} }
child { node {The Girl With All the Gifts (2016) } }
child { node {The Walking Dead (2012) } }
child { node {World War Z (2013) } }
child { node {FEMA Emergency Preparedness Guide (2019) } }
;
\end{tikzpicture}
\end{document}
The first-level branches fan out as intended, but the second-level branches don't:
What should I be doing differently?