Using Forest Package

Question

I am trying to get a hierarchy diagram like this using the Forest package

But, could not managed to get so. I used this code

\documentclass[border=20pt,tikz]{standalone}
\usepackage[edges]{forest}

\forestset{
  direction switch/.style={
    for tree={edge+=thick, font=\sffamily},
    where level>=1{folder, grow'=0}{for children=forked edge},
    where level=3{}{draw},
  },
}
\begin{document}

\begin{forest}
  % forest preamble: determine layout and format of tree
  direction switch
  [Main
  [1.1]
  [1.2]
  [1.3]
  [1.4]
  [2
   [2.1]
   [2.2]
  ]
    [3
   [3.1]
   [3.2]
  ]
    [4
   [4.1]
   [4.2]
  ]
  ]
\end{forest}
\end{document} 

and got instead

Thanks in advance for your help.