Modifying the Cornell Note Template

Question

I'm trying to modify the Cornell Notes template to my specific needs.

1. Is there a way that the red line on the background breaks before and after a section and subsection title?

   I looked through the background documentation and didn't find a option to do that. Is there maybe an option with tikz?

2. What do I have to change so the red \topic boxes are always aligned with the first blue box?

\documentclass[a4paper]{article} 
\usepackage{tcolorbox}
\tcbuselibrary{skins}
\title{
    \vspace{-3em}
    \begin{tcolorbox}[colframe=white,opacityback=0]
        \begin{tcolorbox}
            \Huge\sffamily Cornell Notes on Something

        \end{tcolorbox}
    \end{tcolorbox}
    \vspace{-3em}
}
\date{}
\usepackage{background}
\SetBgScale{1}
\SetBgAngle{0}
\SetBgColor{red}
\SetBgContents{\rule[0em]{4pt}{\textheight}}
\SetBgHshift{-2.3cm}
\SetBgVshift{0cm}
\usepackage{lipsum}% just to generate filler text for the example
\usepackage[margin=2cm]{geometry}
\usepackage{tikz}
\usepackage{tikzpagenodes}
\parindent=0pt
\usepackage{xparse}
\DeclareDocumentCommand\topic{ m m g g g g g}
{
    \begin{tcolorbox}[sidebyside,sidebyside align=top,opacityframe=0,opacityback=0,opacitybacktitle=0, opacitytext=1,lefthand width=.3\textwidth]
        \begin{tcolorbox}[colback=red!05,colframe=red!25,sidebyside align=top,width=\textwidth,before skip=0pt]
            #1.\end{tcolorbox}%
        \tcblower
        \begin{tcolorbox}[colback=blue!05,colframe=blue!10,width=\textwidth,before skip=0pt]
            #2
        \end{tcolorbox}
        \IfNoValueF {#3}{
            \begin{tcolorbox}[colback=blue!05,colframe=blue!10,width=\textwidth]
                #3
            \end{tcolorbox}
        }
        \IfNoValueF {#4}{
            \begin{tcolorbox}[colback=blue!05,colframe=blue!10,width=\textwidth]
                #4
            \end{tcolorbox}
        }
        \IfNoValueF {#5}{
            \begin{tcolorbox}[colback=blue!05,colframe=blue!10,width=\textwidth]
                #5
            \end{tcolorbox}
        }
        \IfNoValueF {#6}{
            \begin{tcolorbox}[colback=blue!05,colframe=blue!10,width=\textwidth]
                #6
            \end{tcolorbox}
        }
        \IfNoValueF {#7}{
            \begin{tcolorbox}[colback=blue!05,colframe=blue!10,width=\textwidth]
                #7
            \end{tcolorbox}
        }
    \end{tcolorbox}
}
\begin{document} 
    \maketitle
\section{This is a long section title }
\topic{This is a question}%
{The first piece of evidence is mandatory}%
{Now add up to five\ldots}%
{\ldots additional pieces of evidence.}

\section{This is an even longer section title}
\topic{Here's another question.}{\lipsum[1]}%
{\lipsum[2]}%


\end{document}

Answer 1

UPDATED after a follow up question

I propose a simpler code using the paracol package that meets both requirements.

Insert the question in the left column using \question {<question text>}

\question ends with \switchcolumn, so the following notes will go automatically to the right column. Insert as many notes as you like in the right column using \note{<note text>}.

When there are multiple questions in the same section, insert \switchcolumn* before the next question to synchronize the columns. A small vertical space can be added to separate the question\notes groups.

\documentclass[a4paper]{article}
\usepackage{paracol} % added <<<<<<<<<<<<<<<<<<<<<
\usepackage{tcolorbox}
\tcbuselibrary{skins}
\usepackage{lipsum}% just to generate filler text for the example
\usepackage[margin=2cm]{geometry}
\newcommand{\question}[1]{% Ask the question
    \begin{tcolorbox}[colback=red!05,colframe=red!25,sidebyside align=top,width=\linewidth,before skip=1ex]
        #1.\end{tcolorbox}% 
        \switchcolumn % now write in the right column

}
\newcommand{\note}[1]{% Add as many notes as you like
    \begin{tcolorbox}[colback=blue!05,colframe=blue!10,width=\linewidth,before skip=1ex]
    #1
\end{tcolorbox}

}
\setcolumnwidth{0.50\textwidth/20pt,0.50\textwidth}% column separation =20pt
\setlength{\columnseprule}{3pt} % column width
\colseprulecolor{red}
\title{%
    \begin{tcolorbox}[before skip = -\baselineskip, after skip =-\baselineskip]
        \centering\Huge\sffamily Cornell Notes on Something

    \end{tcolorbox}
}
\date{} 
\parindent=0pt
\begin{document}
\maketitle
\section{This is a long section title}
\begin{paracol}{2}
    \question{This is a question} 
    \note{The first piece of evidence is mandatory}
    \note{Now add up to five\ldots}%
    \note{\ldots additional pieces of evidence.}
\end{paracol}
\section{This is an even longer section title}
\begin{paracol}{2}

    \question{Here's another question.}
    \note{\lipsum[1]}
    \note{\lipsum[2]}
\end{paracol}
\section{Some subject, several question}
\begin{paracol}{2}
    \question{This is  question I}

    \note{I The first piece of evidence is mandatory}
    \note{Now add up to five\ldots}%
    \note{\ldots additional pieces of evidence.}
    \vspace*{2ex}
\switchcolumn* % go back to the left column ans synchronize &lt;&lt;&lt;&lt;
\question{Here's  question II.}
\note{II The first piece of evidence is mandatory}
\note{Now add up to five\ldots}%
\note{\ldots additional pieces of evidence.}
\vspace*{2ex}

\switchcolumn* % go back to the left column ans synchronize &lt;&lt;&lt;&lt;
\question{And question III.}

\note{III The first piece of evidence is mandatory}
\note{Now add up to five\ldots}%
\note{\ldots additional pieces of evidence.}
\note{\ldots and more \ldots}
\note{\ldots and more.}

\end{paracol}
\end{document}