Reproduce the vertical margins below the environment

Question

In short, I would like to reproduce the vertical margins below the definitions and double bar below the remarks as shown in the following picture:

I've already browsed the posts without any solution. The example in this post is not adequate.

\documentclass{article}
\usepackage{amsthm}
\usepackage[framemethod=tikz]{mdframed}
\usepackage{lipsum}% just to generate text for the example

\newtheorem{theo}{Theorem}
\surroundwithmdframed[outerlinewidth=0.4pt,
  innerlinewidth=0.4pt,
  middlelinewidth=1pt,
  middlelinecolor=white,
  bottomline=false,topline=false,rightline=false]{theo}

\begin{document}

\begin{theo}
\lipsum[4]
\end{theo}

\end{document}

Question: How to have the double bar below the theorem as in the image and so the double waved line?

Answer 1

I have used ntheorem for the indentation (see this answer) and tcolorbox to add the decorations.

\documentclass{article}
\usepackage{lipsum}% just to generate text for the example
\usepackage{ntheorem}

\theoremstyle{plain}
\theoremindent40pt 
\theoremheaderfont{\normalfont\bfseries\hspace{-\theoremindent}}
\newtheorem{theo}{Theorem}[section]
\newtheorem{defin}{Definition}[section]

\usepackage[most]{tcolorbox}
\usetikzlibrary{decorations.pathmorphing}
\tcbuselibrary{skins}
\tcolorboxenvironment{theo}{
    blanker,
    breakable,
    before skip=\topsep,
    after skip=\topsep,
    borderline west={1pt}{20pt}{double, shorten <=12pt}
    }
\tcolorboxenvironment{defin}{
    blanker,
    breakable,
    before skip=\topsep,
    after skip=\topsep,
    borderline west={1pt}{20pt}{decoration={zigzag,amplitude=2pt,pre=moveto,pre length=12pt},decorate}
    }

\begin{document}
\section{My section}
\lipsum[4]
\begin{theo}
\lipsum[4]
\end{theo}
\lipsum[4]
\begin{defin}
\lipsum[4]
\end{defin}
\lipsum[4]
\end{document}