% TC boxes
\tcbset {
  base/.style={
    boxrule=0mm,
    left=1.75mm,
    arc=2mm,
    colbacktitle=black!10!white, 
    coltitle=black, 
    fonttitle=\bfseries,
    toptitle=0.75mm, 
    bottomtitle=0.25mm,
    title={#1}
  }
}
\newtcolorbox{subbox}[1]{
  colframe=black!20!white,
  base={#1}
}

% Math helpers
\def\limxo{\lim_{x\to 0}}
\def\limxi{\lim_{x\to\infty}}
\def\limxn{\lim_{x\to-\infty}}
\def\sumk{\sum_{k=1}^\infty}
\def\sumn{\sum_{n=0}^\infty}
\def\dx{\text{ d}x}

\def\R{\mathbb{R}}
\def\Q{\mathbb{Q}}
\def\N{\mathbb{N}}
\def\C{\mathbb{C}}
\def\Z{\mathbb{Z}}

\def\S{\mathcal{S}}

\def\Def{\overset{\text{def.}}{\iff}}

\def \cgeq{\succcurlyeq}
\def \cleq{\preccurlyeq}

\def \limn{\lim\limits_{n \to \infty}}
\def \limi{\liminf\limits_{n \to \infty}}
\def \lims{\limsup\limits_{n \to \infty}}

\def \ord{\text{ord}}
\def \sep{\ |\ }

\def \iffdef{\overset{\text{def}}{\iff}}

% Titles
\def \definition{\colorbox{lightgray}{Def} }
\def \notation{\colorbox{lightgray}{Notation} }
\def \remark{\colorbox{lightgray}{Remark} }
\def \theorem{\colorbox{lightgray}{Th.} }

% For intuiton and less important notes
\def \subtext#1{
    \color{gray}\footnotesize
    #1
    \color{black}\normalsize
}

% inside tc boxes
\def \smalltext#1{
    \footnotesize
    #1
    \normalsize
}