Same header margins on different pages

Question

Is it possible to set same header margins on pages with different margins?

One guideline of my university is a margin for corrections, but only on pages which contain my solution. I think it would look nicer, if the header margins wouldn't change if I change the page margins.

MWE:

\documentclass[a4paper]{scrartcl}

%\usepackage{fontspec}
\usepackage[ngerman]{babel}
\usepackage[headtopline,headsepline]{scrpage2}
\usepackage{lipsum}
\usepackage{geometry}

\geometry{
  left=25mm,
  right=25mm,
  top=20mm,
  bottom=30mm,
  bindingoffset=5mm
}

\ihead{Hausarbeit\\Dunkle Magie}
\ohead{John Doe\\Mat-Nr. 1234567}

\setkomafont{pageheadfoot}{\small}

\setheadtopline{0pt}
\setheadsepline{0.5pt}
\pagestyle{scrheadings}

\begin{document}

    \author{John Doe}
    \title{Lorem ipsum}
    \maketitle
    \newpage

    \section*{Aufgabe}
    \lipsum[1-3]

    \clearpage
    \newgeometry{
        left=65mm,
        right=25mm,
        top=20mm,
        bottom=30mm,
        bindingoffset=5mm
    }

    \section*{Lösung}
    \lipsum[1-3]
\end{document}

Many thanks!

Edit:

To clarify my question: [I already use \newgeometry, but] I wonder about how can I set a 6.5cm left hand margin just for the content / body and on the same page a left hand header margin of 2.5cm.

Answer 1

With a KOMA-Script class like scrartcl you can use the addmargin environment to change the left or right margin for the content.

Package scrpage2 is depreciated. So I would use its successor scrlayer-scrpage.

\documentclass[%a4paper,% default
  headheight=24pt
]{scrartcl}
\usepackage{fontspec}
\usepackage[ngerman]{babel}
\usepackage{lipsum}

\usepackage[
  manualmark,
  headsepline=.5pt
]{scrlayer-scrpage}% sets pagestyle scrheadings automatically

\usepackage{geometry}
\geometry{
  left=25mm,
  right=25mm,
  top=20mm,
  bottom=30mm,
  bindingoffset=5mm
}

\ihead{Hausarbeit\\Dunkle Magie}
\ohead{John Doe\\Mat-Nr. 1234567}
\setkomafont{pageheadfoot}{\small}

\begin{document}
\author{John Doe}
\title{Lorem ipsum}
\maketitle
\newpage
\addsec*{Aufgabe}
\lipsum[1-3]
\clearpage
\begin{addmargin}[4cm]{0cm}
  \addsec*{Lösung}
  \lipsum[1-3]
\end{addmargin}
\end{document}

There is also a possibility if you want to use \newgeometry:

\documentclass[%a4paper,% default
  headheight=24pt
]{scrartcl}
\usepackage{fontspec}
\usepackage[ngerman]{babel}
\usepackage{lipsum}

\usepackage[
  manualmark,
  headsepline=.5pt
]{scrlayer-scrpage}% sets pagestyle scrheadings automatically

\usepackage{geometry}
\geometry{
  left=25mm,
  right=25mm,
  top=20mm,
  bottom=30mm,
  bindingoffset=5mm
}

\ihead{Hausarbeit\\Dunkle Magie}
\ohead{John Doe\\Mat-Nr. 1234567}
\setkomafont{pageheadfoot}{\small}

\begin{document}
\author{John Doe}
\title{Lorem ipsum}
\maketitle
\newpage
\addsec*{Aufgabe}
\lipsum[1-3]
\newgeometry{
  left=65mm,
  right=25mm,
  top=20mm,
  bottom=30mm,
  bindingoffset=5mm
}
\addsec*{Lösung}
\KOMAoptions{headwidth=\textwidth+4cm:-4cm}
\lipsum[1-3]
\restoregeometry
\KOMAoptions{headwidth=text}
\lipsum
\end{document}

---

If you really want to use the depreciated package scrpage2:

\documentclass[%a4paper,% default
  headheight=24pt
]{scrartcl}
\usepackage{fontspec}
\usepackage[ngerman]{babel}
\usepackage[
  headsepline
]{scrpage2}
\usepackage{lipsum}

\usepackage{geometry}
\geometry{
  left=25mm,
  right=25mm,
  top=20mm,
  bottom=30mm,
  bindingoffset=5mm
}

\ihead{Hausarbeit\\Dunkle Magie}
\ohead{John Doe\\Mat-Nr. 1234567}
\setkomafont{pageheadfoot}{\small}

\setheadsepline{0.5pt}
\pagestyle{scrheadings}

\begin{document}
\author{John Doe}
\title{Lorem ipsum}
\maketitle
\newpage
\addsec*{Aufgabe}
\lipsum[1-3]
\clearpage
\begin{addmargin}[4cm]{0cm}
  \addsec*{Lösung}
  \lipsum[1-3]
\end{addmargin}
\end{document}

or

\documentclass[%a4paper,% default
  headheight=24pt
]{scrartcl}
\usepackage{fontspec}
\usepackage[ngerman]{babel}
\usepackage[
  headsepline
]{scrpage2}
\usepackage{lipsum}

\usepackage{geometry}
\geometry{
  left=25mm,
  right=25mm,
  top=20mm,
  bottom=30mm,
  bindingoffset=5mm
}

\ihead{Hausarbeit\\Dunkle Magie}
\ohead{John Doe\\Mat-Nr. 1234567}
\setkomafont{pageheadfoot}{\small}

\setheadsepline{0.5pt}
\pagestyle{scrheadings}

\begin{document}
\author{John Doe}
\title{Lorem ipsum}
\maketitle
\newpage
\addsec*{Aufgabe}
\lipsum[1-3]
\newgeometry{
  left=65mm,
  right=25mm,
  top=20mm,
  bottom=30mm,
  bindingoffset=5mm
}
\setheadwidth[-4cm]{\dimexpr\textwidth+4cm\relax}
\addsec*{Lösung}% \section* replaced by \addsec*
\lipsum[1-3]
\restoregeometry
\setheadwidth{text}
\lipsum
\end{document}

Answer 2

You have the adjustwidth environment from changepage. It takes two arguments: the values of the width modifications for left and right margins. For two-sided documents, ig the changes are asymmetric, the \checkoddpage command will let you change the inner and outer margins rather than the left and right margins.