\input regression-test.tex
\documentclass{article}
\usepackage{osgstyler}

\DeclareOsgColorPalette{styled-env-test}{
  primary = {model=HTML, value=223344},
  text = {model=HTML, value=111111},
  background = {model=HTML, value=FFFFFF},
  accent = {model=HTML, value=FFD966}
}
\DeclareOsgMetricPalette{styled-env-test}{
  rule = {thin = {.4pt}},
  padding = {compact = {.2em}}
}

\ExplSyntaxOn
\DeclareInstance{osgstyler-block}{block}{standard}{}
\ExplSyntaxOff
\StyleOsgBlockInstance{block}{
  rule-thickness = .4pt, padding = .2em
}

\DeclareOsgNumbering{theorem-number}{
  counter = teststyledtheorem, within = section,
  format = \arabic{section}.\arabic{teststyledtheorem}
}
\DeclareOsgNumbering{note-number}{
  counter = teststylednote
}

\NewOsgStyledEnvironment{stheorem}{block}{theorem-number}{Theorem}
\NewOsgStyledEnvironment{snote}{block}{none}{Note}

\begin{document}
\UseOsgColorPalette{styled-env-test}
\UseOsgMetricPalette{styled-env-test}
\section{One}
\START
\TYPE{counter-exists=\ifcsname c@teststyledtheorem\endcsname yes\else no\fi}
\begin{stheorem}
  First theorem body.
\end{stheorem}
\begin{stheorem}[Named]
  Second theorem body.
\end{stheorem}
\ExplSyntaxOn
\TYPE{theorem-counter-value=\int_use:N \value{teststyledtheorem}}
\ExplSyntaxOff
\begin{snote}
  Unnumbered note body.
\end{snote}
\TYPE{done}
\END
\end{document}