Escape nested list indentation

Question

My goal is to have a list with Arabic numbering, with each Arabic number having a sub-list with Latin numbering. Each Arabic-numbered item represents a general category, with each Latin-numbered item representing a question within that category.

After each question, I want to be able to type up the answer. Thus, I attempted this with an enumerate, another enumerate within that, and then whenever I needed to write a paragraph to answer the question, I would end the inner enumerate, write the paragraph, then resume the enumerate once I've completed it. Example below:

\documentclass{article}

\usepackage{enumitem}

\begin{document}
    \begin{enumerate}
        \item{}

        \begin{enumerate}[label=\roman*)]
            \item{Question:}
        \end{enumerate}

        My answer

        \begin{enumerate}[resume,label=\roman*)]
            \item{Question 2:}
        \end{enumerate}

        My second answer
    \end{enumerate}
\end{document}

The issue with this approach is that the answer text is bound to the outer enumerate's indentation. If I was to exit the outer enumerate as well, I would not be able to re-start the enumerate without re-starting the numbering as well, as I cannot seem to use enumerate without a present item.

As an additional note, I am looking to keep the Latin-numbered list items within the indentation whilst allowing the paragraph text to remain un-indented.

What is the best way for me to obtain the desired effect?

Answer 1

REVISED ANSWER (using \leftskip)

This revised answer will allow pagebreaks in the middle of the answer.

\documentclass{article}
\usepackage{enumitem,lipsum}
\usepackage[pass,showframe]{geometry}
\newcommand\myanswer[1]{{%
  \leftskip-\dimexpr\leftmargini+\leftmarginii\relax #1\par}}
\begin{document}
\begin{enumerate}
    \item{}

    \begin{enumerate}[label=\roman*),parsep=5pt]
        \item Question: What is the margination if my question
          goes on long enough?

    \myanswer{My answer shows that the answer will retain the
      proper margination if one uses the macro
      \textbackslash myanswer.}
    \end{enumerate}


    \begin{enumerate}[resume,label=\roman*),parsep=5pt]
        \item{Question 2:}

    \myanswer{My second answer}
    \end{enumerate}

    \begin{enumerate}[resume, label=\roman*),parsep=5pt]
        \item{Question 3:}

    \myanswer{My third answer \lipsum[4-8]}
    \end{enumerate}
\end{enumerate}
\end{document}

ORIGINAL ANSWER

Maybe something like this, using listparindent to undo indentation for extra paragraphs of an item. The key here for usage is to

1. Make the answer part of the same \item that comprises the question.

2. use \myanswer to typeset your answer, if it is longer than a single line.

The MWE:

\documentclass{article}
\usepackage{enumitem}
\usepackage[pass,showframe]{geometry}
\newcommand\myanswer[1]{\parbox[t]{\textwidth}{#1}}
\begin{document}
\begin{enumerate}
    \item{}

    \begin{enumerate}[label=\roman*),parsep=5pt,
      listparindent=-\dimexpr\leftmargini+\leftmarginii\relax]
        \item Question: What is the margination if my question
          goes on long enough?

    \myanswer{My answer shows that the answer will retain the
      proper margination if one uses the macro
      \textbackslash myanswer.}
    \end{enumerate}


    \begin{enumerate}[resume,label=\roman*),parsep=5pt,
      listparindent=-\dimexpr\leftmargini+\leftmarginii\relax]
        \item{Question 2:}

    \myanswer{My second answer}
    \end{enumerate}

    \begin{enumerate}[resume, label=\roman*),parsep=5pt,
      listparindent=-\dimexpr\leftmargini+\leftmarginii\relax]
        \item{Question 3:}

    \myanswer{My third answer}
    \end{enumerate}
\end{enumerate}
\end{document}

Answer 2

You could use the TeX primitive \parshape to escape the indentation introduced by all list environments. The following should do what you want:

\documentclass{article}

\usepackage{enumitem}
\usepackage{lipsum} %% <- for \lipsum

\makeatletter   %% <- make @ usable in macro names
\newcommand*\answer[1]{%
  \begingroup   %% <- limit scope of the following changes
    \par        %% <- start a new paragraph
    \@totalleftmargin=0pt \linewidth=\columnwidth
    %% ^^ let other commands know that the margins have been reset
    \parshape 0
    %% ^^ reset the margins
    #1\par      %% <- insert #1 and end this paragraph
  \endgroup
}
\makeatother    %% <- revert @

\begin{document}

\lipsum[66]

\begin{enumerate}
\item
    \begin{enumerate}[label=\roman*)]

    \item
        Question 1:
    \answer{\lipsum[75]}

    \item
        Question 2:
    \answer{\lipsum[75]}

    \end{enumerate}
\end{enumerate}

\end{document}

You could alternatively define an answer environment using

\makeatletter %% <- make @ usable in macro names
\newenvironment*{answer}{%
  \par
  \@totalleftmargin=0pt \linewidth=\columnwidth
  \parshape 0
}{\par}
\makeatother %% <- revert @

---

About \parshape:

Under the hood, all list commands use \parshape to change the margins. Though it can be used to do a lot more, if you just want to change the indentation/width of the current (and all subsequent) paragraphs you can call

\@totalleftmargin=<new indentation> \linewidth=<new line width>
\parshape 1 \@totalleftmargin \linewidth

You could also just write \parshape 1 <new indentation> <new width>, but then other commands (such as the list environments) inside the paragraph won't know what margins you have set (and assume the old values). \parshape 0 undoes the effect of previously issued \parshapes.