Hello,

Following on from my previous questions for writing my book (thanks again Wolfgang), I have to create a solution environment like the attached image.

My problem is adjusting the length of the frame.

Thank you.

Fabrice

\setupbodyfont[newcomputermodern-book,11pt]

\defineframed
   [ACFRAME]
   [frame=off,
    width=fit,
    align=flushleft,
    location=low,
    background=color,
    backgroundcolor=lightgray,
    foregroundcolor=,
    foregroundstyle=]


\setupenumerations
  [before={\blank},
   after={\blank},
   alternative=top,
   title=yes,
   titleleft={},
   titleright={},
   titlestyle=bold,
   width=broad]

\defineenumeration
   [exercice]
   [text=Exercice,
    number=yes,
    numbercommand=\groupedcommand{}{.},
    style=italic]

\defineenumeration
   [solution]
   [text=Solution,
    headcommand=\ACFRAME,
    number=no,
    numbercommand=\groupedcommand{}{},
    style=normal]

\starttext

\startexercice{Le nombre d'or est irrationnel}
  Le nombre d'or, noté \m{\phi}, est tel que \m{\phi=\dfrac{1+\sqrt{5}}{2}}. Montrer que \m{\phi} est irrationnel.
\stopexercice

\startsolution
  Nous raisonnons par l'absurde en supposant que \m{\phi} est rationnel.
\stopsolution

\stoptext