Selected tcolorbox styles from NotesTeX (https://github.com/Adhumunt/NotesTeX)

mycolorboxes.sty

%% mycolorboxes.sty:
%% Selected tcolorbox styles from NotesTeX 
%% (https://github.com/Adhumunt/NotesTeX)

\ProvidesPackage{mycolorboxes}

\usepackage[usenames,dvipsnames]{xcolor}
\usepackage[many]{tcolorbox}
\usepackage{thmtools}

% ----------------------------------------------------------------------
%           User Created Environments 
% ----------------------------------------------------------------------

%% Theorem

    \newlength{\spacelength}
    \settowidth{\spacelength}{\normalfont\ }
    \declaretheoremstyle[
        headfont={\bfseries\sffamily\footnotesize},
        notefont={\normalfont},
        bodyfont={\normalfont},
        headpunct={\relax},%\newline,
        headformat={%
            \makebox[0pt][r]{\NAME\ \NUMBER\hspace{\marginparsep}}\hskip-\spacelength{\normalsize\NOTE}},
    ]{theorem}
    
    \tcolorboxenvironment{theorem}{
      boxrule=0pt,
      boxsep=0pt,
      colback={White!90!Dandelion},
      enhanced jigsaw, 
      borderline west={1pt}{0pt}{Dandelion},
      sharp corners,
      before skip=10pt,
      after skip=10pt,
      left=5pt,
      right=5pt,
      breakable,
    }
    
    \declaretheorem[style=theorem]{theorem}
    
    \let\proof\relax
    \let\endproof\relax

%% Proof

    \declaretheoremstyle[
        headfont={\small\scshape},
        notefont={\normalfont},
        bodyfont={\normalfont},
        headpunct={\relax},
        headformat={%
            \makebox[0pt][r]{\NAME\hspace{\marginparsep}}\hskip-\spacelength{\NOTE}},
    ]{proof}
    
    \tcolorboxenvironment{proof}{
      boxrule=0pt,
      boxsep=0pt,
      blanker,
      borderline west={1pt}{0pt}{NavyBlue!80!white},
      before skip=10pt,
      after skip=10pt,
      left=5pt,
      right=5pt,
      breakable,
    }
    
    \declaretheorem[
        style=proof,
        qed=\qedsymbol]{proof}
    
%% Claim

    \declaretheoremstyle[
        headfont={\footnotesize\itshape},
        notefont={\normalfont},
        bodyfont={\normalfont},
        headpunct={\relax},
        headformat={%
            \makebox[0pt][r]{\NAME\hspace{\marginparsep}}\hskip-\spacelength{\NOTE}},
    ]{claim}

%% Question

    \theoremstyle{theorem}
    \newtheorem{ques}{Question}

%% Definition

    \theoremstyle{theorem}
    \newtheorem{definition}{Definition}
    \tcolorboxenvironment{definition}{
      boxrule=0pt,
      boxsep=0pt,
      colback={White!90!Cerulean},
      enhanced jigsaw, 
      borderline west={1pt}{0pt}{Cerulean},
      sharp corners,
      before skip=10pt,
      after skip=10pt,
      left=5pt,
      right=5pt,
      breakable,
    }

%% Lemma

    \theoremstyle{theorem}
    \newtheorem{lemma}{Lemma}
    \tcolorboxenvironment{lemma}{
      boxrule=0pt,
      boxsep=0pt,
      blanker,
      borderline west={1pt}{0pt}{Red},
      before skip=10pt,
      after skip=10pt,
      sharp corners,
      left=5pt,
      right=5pt,
      breakable,
    }

%% Intuition

    \declaretheorem[style=claim]{Intuition}
    \theoremstyle{claim}
    \newtheorem{intu}{Intuition}

%% Solution

    \theoremstyle{claim}
    \newtheorem{solu}{Solution}

%% Remark

    \theoremstyle{claim}
    \newtheorem{remark}{Remark}

%% Example

    \theoremstyle{claim}
    \newtheorem{example}{Example}
    \tcolorboxenvironment{example}{
      boxrule=0pt,
      boxsep=0pt,
      blanker,
      borderline west={1pt}{0pt}{Black},
      sharp corners,
      before skip=10pt,
      after skip=10pt,
      left=5pt,
      right=5pt,
      breakable,
    }