Fancy remark environment

Question

I have this:

\usepackage{picins}
\shadowthickness{2pt}
\newcommand{\sidenote}[1]{
    \begin{center}
    \hpic(0.95\textwidth,0pt)[rs]{
        \parbox[b]{0.9\textwidth}{\small
             \bigskip{#1}\bigskip
        }
    }
    \end{center}
}

Which generates a nice (shadowed) box with padding. The problem is that \sidenote cannot accept formatted text (i.e. paragraphs).

Is it possible to define a "FancyRemark" environment which has the same visual style but does allow for paragraphs and display style math?

Answer 1

Sorry, picins somehow does not seem to work at the moment, on this machine.

This is what I guess you wanted:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shadows}
\usepackage{environ}
\NewEnviron{sidenote}{%
  \begin{tikzpicture}[font=\normalsize]
      \node [text width=0.9\linewidth,draw,drop shadow,fill=white,inner sep=10pt]{%
           \BODY
        };
   \end{tikzpicture}
}
\begin{document}
\begin{sidenote}
  sfasdfasdfasdf
\begin{equation}
1+2=3
\end{equation}
\end{sidenote}
\end{document}

Please give me a preview, if you want me to tweak the looks to your expectations.

Answer 2

Here are some options using environments defined with the help of the mdframed and tcolorbox packages; the advantage of using these packages is that the offer an easy customization mechanism and the frames allow page breaks:

\documentclass{article}
\usepackage{picins}
\usepackage[most]{tcolorbox}
\usepackage[framemethod=tikz]{mdframed}
\usetikzlibrary{shadows}

\newmdenv[
leftmargin=10pt,
rightmargin=10pt,
innertopmargin=10pt,
innerbottommargin=10pt,
shadow=true,
]{mdsidenote}

\newtcolorbox{tsidenote}{
breakable,
enhanced,
colback=white,
width=\dimexpr\linewidth-20pt\relax,
enlarge left by=10pt,
shadow={1mm}{-1mm}{0mm}{black!40}
}

\shadowthickness{2pt}
\newcommand{\sidenote}[1]{
    \begin{center}
    \hpic(0.95\textwidth,0pt)[rs]{
        \parbox[b]{0.9\textwidth}{\small
             \bigskip{#1}\bigskip
        }
    }
    \end{center}
}

\newcommand\Text{% just to generate text for the example
Quisque ullamcorper placerat ipsum. Cras nibh. Morbi vel justo vitae lacus
tincidunt ultrices. Lorem ipsum dolor sit amet, consectetuer adipiscing elit. In hac habitasse platea dictumst.}

\begin{document}

\sidenote{some text goes here}

\begin{mdsidenote}
Some text inside the environment; a displayed expression and some paragraphs:
\[
a + b = c + d+ e.
\]
\Text\par\Text
\end{mdsidenote}

\begin{tsidenote}
Some text inside the environment; a displayed expression and some paragraphs:
\[
a + b = c + d+ e.
\]
\Text\par\Text
\end{tsidenote}

\end{document}