Space between text and upper line in mdframed

Question

I am using the following code:

\documentclass[11pt,a4paper,twoside]{book}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[english]{babel}

\usepackage{mdframed}
\theoremstyle{definition}
\newmdtheoremenv[linewidth=1.1pt]{Definition}{Definition}[chapter]

\begin{document}

\begin{Definition} (blah blah)\newline
Text...
\end{Definition}

\end{document}

which produces

Is it possible to reduce the space between the first line of text and the upper black line?

Thank you in advance!

Answer 1

That extra top skip is produced by \topskip. Reduce \topskip from mdframed option innertopmargin's default value (5pt) solves the problem..

\documentclass[11pt,a4paper,twoside]{book}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[english]{babel}

\usepackage{amsthm}   % provide \theoremstyle
\usepackage{mdframed}

\theoremstyle{definition}
\newmdtheoremenv[
    linewidth=1.1pt, 
    innertopmargin=\dimexpr5pt-\topskip\relax]
  {Definition}{Definition}[chapter]

\begin{document}
\begin{Definition} (blah blah)\newline
  Text...
\end{Definition}
\end{document}

Answer 2

Is this better?

\documentclass[11pt,a4paper,twoside]{book}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[english]{babel}
\usepackage{amsthm}

\usepackage{mdframed}
\theoremstyle{definition}
\newmdtheoremenv[linewidth=1.1pt, innertopmargin=-2pt, innerbottommargin=7pt]{Definition}{Definition}[chapter]

\begin{document}

\begin{Definition} (blah blah)\newline
Text...
\end{Definition}

\end{document}