\usepackage{cancel}
\usepackage{tikz}
\usepackage{pgfplots}
\usepackage{enumitem}

%--------------------------%

\renewcommand{\theenumi}{\arabic{enumi}}
\renewcommand{\labelenumi}{\Large\fbox{\theenumi}}

\newenvironment{oppgaver}{
  \begin{enumerate}
}
{
  \end{enumerate}
}

\newcommand{\setoppg}[1]{\setcounter{enumi}{#1}}

\newcommand{\oppg}{
  \item
  \addcontentsline{toc}{subsection}{Oppgave \theenumi}
}

%--------------------------%

\renewcommand{\theenumii}{\alph{enumii})}
\renewcommand{\labelenumii}{\textbf{\theenumii}}

\newenvironment{deloppgaver}{
  \begin{enumerate}
}{
  \end{enumerate}
}

\newcommand{\setdelo}[1]{\setcounter{enumii}{#1}}

\newcommand{\delo}{
  \vspace*{0.5cm}
  \item
  \addcontentsline{toc}{subsubsection}{\theenumii}
}

%--------------------------%

\newtcolorbox{coloredgraphbox}{
  colframe=ntnublue,
  arc=0pt,
  outer arc=0pt
  colback=white,
  boxrule=3pt
}

\newenvironment{graphbox}{
  \begin{center}
  \begin{coloredgraphbox}
}{
  \end{coloredgraphbox}
  \end{center}
}