%% ===========================================================================
%%  pubarx.cls -- LaTeX class for PubArx preprints
%%  Version 1.0 (2026-10-29)
%%
%%  A refined two-column layout for research papers posted on PubArx
%%  (https://pubarx.com): a full-width title block with ORCID-linked authors,
%%  a tinted abstract panel, colour-accented headings, booktabs-friendly
%%  tables, numbered natbib citations and complete PDF metadata, which
%%  Google Scholar and other indexers read.
%%
%%  Engine:  pdfLaTeX + BibTeX (on Overleaf: Menu > Compiler > pdfLaTeX).
%%  Manual:  README.md.  Worked example: main.tex.
%%
%%  Licence: MIT No Attribution (MIT-0). Use, change and share this file
%%  freely, for any paper, without keeping this notice. See LICENSE.
%% ===========================================================================
\NeedsTeXFormat{LaTeX2e}[2020/10/01]
\ProvidesClass{pubarx}[2026/10/29 v1.0 PubArx preprint class]

%% ---------------------------------------------------------------------------
%% 1. Class options
%%
%%    a4paper (default) | letterpaper   paper size
%%    twocolumn (default) | onecolumn   page layout
%%    10pt | 11pt | 12pt                body size (default: 10pt in two
%%                                      columns, 11pt in one column)
%%    font=libertinus | newtx | lm      typeface (default libertinus); the
%%                                      bare words libertinus, newtx and lm
%%                                      work as options too
%%    review                            line numbers and wider line spacing
%%    columnrule                        thin rule between the two columns
%%    nologo                            no PubArx band on the first page
%%    notheorems                        do not predefine theorem environments
%%
%%    Any other option (draft, fleqn, leqno, ...) is passed to article.cls.
%% ---------------------------------------------------------------------------
\RequirePackage{kvoptions}
\SetupKeyvalOptions{family=pubarx,prefix=pubarx@}

\DeclareStringOption[libertinus]{font}
\DeclareVoidOption{libertinus}{\def\pubarx@font{libertinus}}
\DeclareVoidOption{newtx}{\def\pubarx@font{newtx}}
\DeclareVoidOption{lm}{\def\pubarx@font{lm}}

\DeclareBoolOption{review}
\DeclareBoolOption{columnrule}
\DeclareBoolOption{nologo}
\DeclareBoolOption{notheorems}

\newif\ifpubarx@twocol
\pubarx@twocoltrue
\DeclareVoidOption{twocolumn}{\pubarx@twocoltrue}
\DeclareVoidOption{onecolumn}{\pubarx@twocolfalse}

\def\pubarx@paper{a4paper}
\DeclareVoidOption{a4paper}{\def\pubarx@paper{a4paper}}
\DeclareVoidOption{letterpaper}{\def\pubarx@paper{letterpaper}}

\def\pubarx@ptsize{}
\DeclareVoidOption{10pt}{\def\pubarx@ptsize{10pt}}
\DeclareVoidOption{11pt}{\def\pubarx@ptsize{11pt}}
\DeclareVoidOption{12pt}{\def\pubarx@ptsize{12pt}}

\DeclareDefaultOption{\PassOptionsToClass{\CurrentOption}{article}}
\ProcessKeyvalOptions*

%% ---------------------------------------------------------------------------
%% 2. Base class
%% ---------------------------------------------------------------------------
\ifx\pubarx@ptsize\@empty
  \ifpubarx@twocol
    \def\pubarx@ptsize{10pt}
  \else
    \def\pubarx@ptsize{11pt}
  \fi
\fi
\ifpubarx@twocol
  \def\pubarx@columns{twocolumn}
\else
  \def\pubarx@columns{onecolumn}
\fi
\edef\pubarx@loadclass{%
  \noexpand\LoadClass[\pubarx@paper,\pubarx@ptsize,\pubarx@columns]{article}}
\pubarx@loadclass

%% ---------------------------------------------------------------------------
%% 3. Encoding, mathematics and fonts
%%
%%    Libertinus is the default: an elegant, open-source book face with true
%%    small capitals, a matching sans for headings and a full maths font, so
%%    papers look distinctive without looking unusual. newtx (Times-like) is
%%    the conservative alternative many journals expect; lm (Latin Modern)
%%    is the safety net that every TeX installation has. If a requested font
%%    is not installed, the class falls back to the next one with a warning.
%%
%%    amsthm must be loaded before newtxmath / libertinust1math, and amssymb
%%    is only needed for Latin Modern (the other two provide its symbols).
%% ---------------------------------------------------------------------------
\RequirePackage{iftex}
\ifPDFTeX
  \RequirePackage[utf8]{inputenc}% no-op on current LaTeX, harmless before
\fi
\RequirePackage[T1]{fontenc}
\RequirePackage{amsmath}
\RequirePackage{amsthm}

\def\pubarx@f@libertinus{libertinus}
\def\pubarx@f@newtx{newtx}
\def\pubarx@f@lm{lm}
\edef\pubarx@fontchoice{\pubarx@font}

% Normalise the option value.
\ifx\pubarx@fontchoice\pubarx@f@newtx\else
  \ifx\pubarx@fontchoice\pubarx@f@lm\else
    \ifx\pubarx@fontchoice\pubarx@f@libertinus\else
      \ClassWarningNoLine{pubarx}{Unknown font `\pubarx@fontchoice'.\MessageBreak
        Use font=libertinus, newtx or lm. Using Libertinus}%
    \fi
    \let\pubarx@fontchoice\pubarx@f@libertinus
  \fi
\fi

% Fall back gracefully when a font is not installed.
\newif\ifpubarx@fontfound
\ifx\pubarx@fontchoice\pubarx@f@libertinus
  \IfFileExists{libertinus-type1.sty}{\pubarx@fontfoundtrue}{\pubarx@fontfoundfalse}
  \ifpubarx@fontfound
    \IfFileExists{libertinust1math.sty}{}{\pubarx@fontfoundfalse}
  \fi
  \ifpubarx@fontfound\else
    \ClassWarningNoLine{pubarx}{Libertinus fonts not found. Using newtx}%
    \let\pubarx@fontchoice\pubarx@f@newtx
  \fi
\fi
\ifx\pubarx@fontchoice\pubarx@f@newtx
  \IfFileExists{newtxtext.sty}{\pubarx@fontfoundtrue}{\pubarx@fontfoundfalse}
  \ifpubarx@fontfound
    \IfFileExists{newtxmath.sty}{}{\pubarx@fontfoundfalse}
  \fi
  \ifpubarx@fontfound\else
    \ClassWarningNoLine{pubarx}{newtx fonts not found. Using Latin Modern}%
    \let\pubarx@fontchoice\pubarx@f@lm
  \fi
\fi

\ifx\pubarx@fontchoice\pubarx@f@libertinus
  \RequirePackage{libertinus-type1}
  \RequirePackage{libertinust1math}
\else
  \ifx\pubarx@fontchoice\pubarx@f@newtx
    \RequirePackage{newtxtext}
    \RequirePackage{newtxmath}
  \else
    \RequirePackage{lmodern}
    \RequirePackage{amssymb}
  \fi
\fi

% newtxmath and libertinust1math already define every amssymb symbol, and
% loading amssymb after them fails. Mark it as loaded so that a habitual
% \usepackage{amssymb} in a preamble is accepted and ignored.
\ifx\pubarx@fontchoice\pubarx@f@lm\else
  \@ifpackageloaded{amssymb}{}{%
    \@namedef{ver@amssymb.sty}{2013/01/14 v3.01 AMS font symbols (from the maths font)}}
\fi

\RequirePackage{microtype}

%% ---------------------------------------------------------------------------
%% 4. Colours (usable in your own figures, e.g. draw=pubarxnavy)
%%    xcolor is loaded with the options papers ask for most often, so that
%%    \usepackage[dvipsnames]{xcolor} or [table] in a preamble do not clash.
%%    For other options write \PassOptionsToPackage{...}{xcolor} before
%%    \documentclass.
%% ---------------------------------------------------------------------------
\RequirePackage[usenames,dvipsnames,table]{xcolor}
\definecolor{pubarxnavy}{HTML}{1E3A6E}
\definecolor{pubarxaccent}{HTML}{C2552C}
\definecolor{pubarxaccentlight}{HTML}{E98A62}
\definecolor{pubarxmuted}{HTML}{4D5668}
\definecolor{pubarxrule}{HTML}{CFC9BC}
\definecolor{pubarxorcid}{HTML}{A6CE39}
\colorlet{pubarxtint}{pubarxnavy!6}
\colorlet{pubarxwarm}{pubarxaccent!7}
\colorlet{pubarxbandmuted}{white!70!pubarxnavy}

%% ---------------------------------------------------------------------------
%% 5. Page layout
%% ---------------------------------------------------------------------------
\RequirePackage{graphicx}
\RequirePackage{geometry}
\def\pubarx@letter{letterpaper}
\ifx\pubarx@paper\pubarx@letter
  \geometry{letterpaper}
\else
  \geometry{a4paper}
\fi
\ifpubarx@twocol
  \geometry{hmargin=17mm,top=24mm,bottom=25mm,headheight=14pt,headsep=6mm,
    footskip=11mm,columnsep=6.5mm,heightrounded}
\else
  \geometry{hmargin=31mm,top=27mm,bottom=27mm,headheight=14pt,headsep=7mm,
    footskip=12mm,heightrounded}
\fi

\ifpubarx@columnrule
  \setlength\columnseprule{0.4pt}
  \providecommand\columnseprulecolor{}
  \renewcommand\columnseprulecolor{\color{pubarxrule}}
\fi

% Calm, even paragraphs in narrow columns.
\frenchspacing
\clubpenalty=3000
\widowpenalty=3000
\displaywidowpenalty=1500
\tolerance=2000
\emergencystretch=1.5em
\ifpubarx@review
  \linespread{1.5}
\fi

% Let floats sit at the top of columns instead of piling up at the end.
\renewcommand\topfraction{0.85}
\renewcommand\bottomfraction{0.5}
\renewcommand\textfraction{0.12}
\renewcommand\floatpagefraction{0.8}
\renewcommand\dbltopfraction{0.85}
\renewcommand\dblfloatpagefraction{0.8}
\setcounter{topnumber}{3}
\setcounter{bottomnumber}{2}
\setcounter{totalnumber}{4}
\setcounter{dbltopnumber}{2}

\renewcommand\footnoterule{%
  \kern-3\p@{\color{pubarxrule}\hrule\@width.3\columnwidth}\kern2.6\p@}

%% ---------------------------------------------------------------------------
%% 6. Section headings: navy sans-serif titles, terracotta numbers
%% ---------------------------------------------------------------------------
\RequirePackage{titlesec}
\newcommand\pubarx@headingfont{\normalfont\sffamily\bfseries\color{pubarxnavy}}
\titleformat{\section}
  {\pubarx@headingfont\large\filright}
  {\textcolor{pubarxaccent}{\thesection}}{0.6em}{}
\titleformat{\subsection}
  {\pubarx@headingfont\normalsize\filright}
  {\textcolor{pubarxaccent}{\thesubsection}}{0.55em}{}
\titleformat{\subsubsection}
  {\normalfont\normalsize\itshape\color{pubarxnavy}\filright}
  {\thesubsubsection}{0.5em}{}
\titleformat{\paragraph}[runin]
  {\normalfont\normalsize\bfseries\color{pubarxnavy}}
  {\theparagraph}{0.5em}{}
\titlespacing*{\section}{0pt}{3ex plus 1ex minus .4ex}{1.2ex plus .3ex}
\titlespacing*{\subsection}{0pt}{2.2ex plus .8ex minus .3ex}{0.8ex plus .2ex}
\titlespacing*{\subsubsection}{0pt}{1.8ex plus .6ex minus .3ex}{0.5ex plus .2ex}
\titlespacing*{\paragraph}{0pt}{1.4ex plus .5ex minus .2ex}{0.8em}

% Appendix sections read "Appendix A", "Appendix B", ...
\g@addto@macro\appendix{%
  \titleformat{\section}
    {\pubarx@headingfont\large\filright}
    {\textcolor{pubarxaccent}{\appendixname\ \thesection}}{0.6em}{}}

%% ---------------------------------------------------------------------------
%% 7. Captions, tables and lists
%% ---------------------------------------------------------------------------
\RequirePackage{booktabs}
\RequirePackage{caption}
\DeclareCaptionFont{pubarxnavy}{\color{pubarxnavy}}
\DeclareCaptionLabelSeparator{pubarxbar}{%
  \hspace{0.5em}\textcolor{pubarxaccent}{\rule[-0.1em]{0.6pt}{0.85em}}\hspace{0.5em}}
\captionsetup{font=small,labelfont={sf,bf,pubarxnavy},labelsep=pubarxbar,
  justification=justified,singlelinecheck=true,skip=6pt}
\captionsetup[table]{position=top}

\RequirePackage{enumitem}
\setlist{topsep=3pt plus 1pt minus 1pt,partopsep=0pt,itemsep=1.5pt plus 1pt,parsep=0pt}
\setlist[itemize]{leftmargin=1.3em}
\setlist[itemize,1]{label=\textcolor{pubarxaccent}{\ensuremath{\bullet}}}
\setlist[itemize,2]{label=\textcolor{pubarxnavy}{\ensuremath{\circ}}}
\setlist[enumerate,1]{font=\sffamily\bfseries\color{pubarxnavy}}

%% ---------------------------------------------------------------------------
%% 8. Theorems and proofs
%%    theorem, lemma, proposition, corollary, conjecture (italic body);
%%    definition, example, assumption (upright); remark (upright, light head).
%%    They share one counter. Disable them with the notheorems option.
%% ---------------------------------------------------------------------------
\newtheoremstyle{pubarxplain}
  {6pt plus 2pt minus 1pt}{6pt plus 2pt minus 1pt}
  {\itshape}{}
  {\sffamily\bfseries\color{pubarxnavy}}{.}{0.5em}
  {\thmname{#1}\thmnumber{ #2}\thmnote{ {\mdseries(#3)}}}
\newtheoremstyle{pubarxdefinition}
  {6pt plus 2pt minus 1pt}{6pt plus 2pt minus 1pt}
  {\normalfont}{}
  {\sffamily\bfseries\color{pubarxnavy}}{.}{0.5em}
  {\thmname{#1}\thmnumber{ #2}\thmnote{ {\mdseries(#3)}}}
\newtheoremstyle{pubarxremark}
  {6pt plus 2pt minus 1pt}{6pt plus 2pt minus 1pt}
  {\normalfont}{}
  {\sffamily\itshape\color{pubarxnavy}}{.}{0.5em}
  {\thmname{#1}\thmnumber{ #2}\thmnote{ (#3)}}

\ifpubarx@notheorems\else
  \theoremstyle{pubarxplain}
  \newtheorem{theorem}{Theorem}
  \newtheorem{lemma}[theorem]{Lemma}
  \newtheorem{proposition}[theorem]{Proposition}
  \newtheorem{corollary}[theorem]{Corollary}
  \newtheorem{conjecture}[theorem]{Conjecture}
  \theoremstyle{pubarxdefinition}
  \newtheorem{definition}[theorem]{Definition}
  \newtheorem{example}[theorem]{Example}
  \newtheorem{assumption}[theorem]{Assumption}
  \theoremstyle{pubarxremark}
  \newtheorem{remark}[theorem]{Remark}
\fi
% Theorems you define yourself get the plain PubArx style by default.
\theoremstyle{pubarxplain}

% The amsthm proof environment, with a sans-serif head and a terracotta
% end-of-proof square. Use \qedhere to put the square on a display line.
\renewenvironment{proof}[1][\proofname]{\par
  \pushQED{\qed}%
  \normalfont\topsep6\p@\@plus6\p@\relax
  \trivlist
  \item[\hskip\labelsep\sffamily\itshape\color{pubarxnavy}#1\@addpunct{.}]\ignorespaces
}{%
  \popQED\endtrivlist\@endpefalse
}
\renewcommand\qedsymbol{\textcolor{pubarxaccent}{\rule{0.45em}{0.45em}}}

%% ---------------------------------------------------------------------------
%% 9. Citations and references: numbered, sorted and compressed ([1-3]).
%%    Use \citep{key} for [1] and \citet{key} for "Author et al. [1]".
%% ---------------------------------------------------------------------------
\RequirePackage[numbers,square,comma,sort&compress]{natbib}
\setlength\bibsep{2pt plus 1pt minus 0.5pt}
\def\bibfont{\small}
\def\bibnumfmt#1{\textcolor{pubarxnavy}{[#1]}}
\def\bibsection{%
  \phantomsection\addcontentsline{toc}{section}{\refname}%
  \section*{\refname}}

%% ---------------------------------------------------------------------------
%% 10. Review mode: line numbers
%% ---------------------------------------------------------------------------
\ifpubarx@review
  \ifpubarx@twocol
    \RequirePackage[switch]{lineno}
  \else
    \RequirePackage{lineno}
  \fi
  \renewcommand\linenumberfont{\normalfont\tiny\sffamily\color{pubarxmuted}}
  \setlength\linenumbersep{8pt}
  \AtBeginDocument{\linenumbers}
\fi

%% ---------------------------------------------------------------------------
%% 11. Running heads and feet
%%     First page: licence on the left, "Page 1 of N" on the right.
%%     Other pages: short title | PubArx identifier; running authors | page.
%% ---------------------------------------------------------------------------
\RequirePackage{fancyhdr}
\RequirePackage{lastpage}

%% ---------------------------------------------------------------------------
%% 12. Links and PDF metadata (filled in by \maketitle)
%% ---------------------------------------------------------------------------
\RequirePackage{url}
\RequirePackage[hyperfootnotes=false]{hyperref}
\hypersetup{
  colorlinks=true,
  linkcolor=pubarxnavy,
  citecolor=pubarxaccent,
  urlcolor=pubarxnavy,
  filecolor=pubarxnavy,
  bookmarksnumbered=true,
  bookmarksopen=true,
  pdfpagemode=UseNone,
  pdfdisplaydoctitle=true,
  pdfcreator={LaTeX with the PubArx class v1.0}
}
\urlstyle{same}
\pdfstringdefDisableCommands{%
  \def\\{ }%
  \def\and{, }%
  \let\thanks\@gobble
  \let\footnote\@gobble
  \let\textsuperscript\@gobble
  \let\orcid\@gobble
  \let\orcidlink\@gobble
}

% ORCID icons: the orcidlink package draws the official logo. If it is not
% installed, a small green "iD" link is used instead.
\newif\ifpubarx@orcidlink
\IfFileExists{orcidlink.sty}{\pubarx@orcidlinktrue}{\pubarx@orcidlinkfalse}
\ifpubarx@orcidlink
  \RequirePackage{orcidlink}
  \newcommand\pubarx@orcidlink[1]{\orcidlink{#1}}
\else
  \newcommand\pubarx@orcidlink[1]{%
    \href{https://orcid.org/#1}{\textcolor{pubarxorcid}{\sffamily\bfseries\scriptsize iD}}}
\fi

% DOIs in the bibliography become links (unsrtnat and plainnat call \doi).
\providecommand*\doi[1]{\href{https://doi.org/#1}{\nolinkurl{https://doi.org/#1}}}

% Where identifiers point. Redefine only if PubArx tells you to.
\newcommand\pubarxbaseurl{https://pubarx.com}

%% ---------------------------------------------------------------------------
%% 13. Title-page commands
%% ---------------------------------------------------------------------------
\newcommand\pubarx@ifblank[3]{% #1: macro; #2: code if empty; #3: otherwise
  \if\relax\detokenize\expandafter{#1}\relax
    \expandafter\@firstoftwo
  \else
    \expandafter\@secondoftwo
  \fi{#2}{#3}}

\newcommand\pubarx@needauthor[1]{%
  \ClassError{pubarx}{\string#1 must follow an \string\author\space command}%
    {Write \string#1 directly after the \string\author\space it belongs to.}}

% \title[Short title for the running head]{Full title}
\def\pubarx@title{}
\def\pubarx@shorttitle{}
\renewcommand\title[2][]{%
  \gdef\pubarx@title{#2}%
  \gdef\@title{#2}%
  \if\relax\detokenize{#1}\relax
    \gdef\pubarx@shorttitle{#2}%
  \else
    \gdef\pubarx@shorttitle{#1}%
  \fi}

% \author[1,2]{Given Family} -- one command per author, in order; the
% optional argument lists affiliation labels. Follow it with \orcid{...},
% \corresponding{email} and \equalcontrib as needed.
\newcount\pubarx@nauthors
\newcount\pubarx@ncorr
\newif\ifpubarx@hasequal
\def\pubarx@authors{}
\def\pubarx@pdfauthors{}
\def\pubarx@currentname{}
\def\pubarx@corrlist{}
\renewcommand\author[2][]{%
  \global\advance\pubarx@nauthors\@ne
  \gdef\pubarx@currentname{#2}%
  \expandafter\pubarx@addauthor\expandafter{\the\pubarx@nauthors}{#1}{#2}}
\newcommand\pubarx@addauthor[3]{% #1: number, #2: labels, #3: name
  \g@addto@macro\pubarx@authors{\pubarx@authorentry{#1}{#3}{#2}}%
  \ifnum#1=\@ne
    \g@addto@macro\pubarx@pdfauthors{#3}%
  \else
    \g@addto@macro\pubarx@pdfauthors{, #3}%
  \fi}
\renewcommand\and{\unskip, }

\DeclareRobustCommand\orcid[1]{%
  \ifnum\pubarx@nauthors=\z@
    \pubarx@needauthor\orcid
  \else
    \expandafter\gdef\csname pubarx@orcid@\the\pubarx@nauthors\endcsname{#1}%
  \fi}
\DeclareRobustCommand\corresponding[1]{%
  \ifnum\pubarx@nauthors=\z@
    \pubarx@needauthor\corresponding
  \else
    \global\advance\pubarx@ncorr\@ne
    \expandafter\gdef\csname pubarx@corr@\the\pubarx@nauthors\endcsname{#1}%
    \expandafter\pubarx@addcorr\expandafter{\pubarx@currentname}{#1}%
  \fi}
\newcommand\pubarx@addcorr[2]{%
  \g@addto@macro\pubarx@corrlist{\pubarx@correntry{#1}{#2}}}
\DeclareRobustCommand\equalcontrib{%
  \ifnum\pubarx@nauthors=\z@
    \pubarx@needauthor\equalcontrib
  \else
    \global\pubarx@hasequaltrue
    \expandafter\gdef\csname pubarx@equal@\the\pubarx@nauthors\endcsname{}%
  \fi}

% \affiliation[1]{Department, Institution, City, Country}
\def\pubarx@affiliations{}
\DeclareRobustCommand\affiliation[2][]{%
  \g@addto@macro\pubarx@affiliations{\pubarx@affentry{#1}{#2}}}
\newcommand\address{\affiliation}% for authors coming from elsarticle

% \keywords{first keyword, second keyword, ...}
\def\pubarx@keywords{}
\DeclareRobustCommand\keywords[1]{\gdef\pubarx@keywords{#1}}

% PubArx band and metadata
\def\pubarx@id{}
\def\pubarx@version{}
\def\pubarx@fullid{}
\def\pubarx@status{Preprint -- not peer reviewed}
\def\pubarx@license{CC BY 4.0}
\def\pubarx@subject{}
% The full identifier ("2026.00042v2") stays empty until \pubarxid is given,
% so a lone \pubarxversion never produces a broken "PubArx:v2" link.
\newcommand\pubarx@updateid{%
  \pubarx@ifblank\pubarx@id
    {\global\let\pubarx@fullid\@empty}%
    {\pubarx@ifblank\pubarx@version
      {\global\let\pubarx@fullid\pubarx@id}%
      {\protected@xdef\pubarx@fullid{\pubarx@id v\pubarx@version}}}}
\DeclareRobustCommand\pubarxid[1]{\gdef\pubarx@id{#1}\pubarx@updateid}
\DeclareRobustCommand\pubarxversion[1]{\gdef\pubarx@version{#1}\pubarx@updateid}
\DeclareRobustCommand\pubarxstatus[1]{\gdef\pubarx@status{#1}}
\DeclareRobustCommand\pubarxlicense[1]{\gdef\pubarx@license{#1}}
\DeclareRobustCommand\pubarxsubject[1]{\gdef\pubarx@subject{#1}}

% Dates and running author line
\def\pubarx@received{}
\def\pubarx@revised{}
\def\pubarx@accepted{}
\def\pubarx@posted{}
\def\pubarx@runningauthor{}
\DeclareRobustCommand\received[1]{\gdef\pubarx@received{#1}}
\DeclareRobustCommand\revised[1]{\gdef\pubarx@revised{#1}}
\DeclareRobustCommand\accepted[1]{\gdef\pubarx@accepted{#1}}
\DeclareRobustCommand\posted[1]{\gdef\pubarx@posted{#1}}
\DeclareRobustCommand\runningauthor[1]{\gdef\pubarx@runningauthor{#1}}

\providecommand\keywordsname{Keywords}
\providecommand\highlightsname{Highlights}
% article.cls (unlike report and book) may not define \appendixname, which
% the appendix headings use.
\providecommand\appendixname{Appendix}

%% ---------------------------------------------------------------------------
%% 14. Title-block typography
%% ---------------------------------------------------------------------------
\newcommand\pubarx@leading[1]{\@tempdima=\f@size\p@\baselineskip=#1\@tempdima\relax}
\newcommand\pubarx@titlefont{%
  \normalfont\huge\bfseries\color{pubarxnavy}\raggedright
  \pubarx@leading{1.12}\hyphenpenalty\@M\exhyphenpenalty\@M}
\newcommand\pubarx@authorfont{%
  \normalfont\large\raggedright\pubarx@leading{1.35}}
\newcommand\pubarx@afffont{%
  \normalfont\footnotesize\color{pubarxmuted}\raggedright\pubarx@leading{1.3}}
\newcommand\pubarx@metafont{%
  \normalfont\sffamily\footnotesize\color{pubarxmuted}\raggedright}
\newcommand\pubarx@eyebrowfont{%
  \normalfont\sffamily\bfseries\scriptsize\color{pubarxaccent}\raggedright}
\newcommand\pubarx@labelfont{%
  \normalfont\sffamily\bfseries\footnotesize\color{pubarxnavy}}
\newcommand\pubarx@bandfont{\normalfont\sffamily\footnotesize\color{white}}
\newcommand\pubarx@spaced[1]{\textls[60]{#1}}
\newcommand\pubarx@corrsymbol{\ensuremath{\ast}}
\newcommand\pubarx@equalsymbol{\ensuremath{\dagger}}

% Separated lists ("a . b . c") for the band, the eyebrow and the dates.
\newif\ifpubarx@listfirst
\newif\ifpubarx@hasitems
\newcommand\pubarx@liststart{\global\pubarx@listfirsttrue}
\newcommand\pubarx@listsep{\unskip\nobreak\hspace{0.5em}\ensuremath{\cdot}\hspace{0.5em}}
\newcommand\pubarx@listitem[1]{%
  \ifpubarx@listfirst\global\pubarx@listfirstfalse\else\pubarx@listsep\fi
  #1}

%% ---------------------------------------------------------------------------
%% 15. Title-block pieces
%% ---------------------------------------------------------------------------
\newsavebox\pubarx@abstractbox
\newsavebox\pubarx@highlightsbox
\newsavebox\pubarx@tmpbox
\newdimen\pubarx@panelpad
\newdimen\pubarx@barwidth
\pubarx@panelpad=9pt
\pubarx@barwidth=2.4pt

\newcommand\pubarx@idlink[1]{% #1: text style
  \href{\pubarxbaseurl/abs/\pubarx@fullid}{#1PubArx:\pubarx@fullid}}

% The slim navy band at the top of page 1.
\newcommand\pubarx@band{%
  \par
  \begingroup
    \fboxsep\z@
    \setbox\pubarx@tmpbox\hbox to\textwidth{%
      \pubarx@bandfont
      \vrule\@width\z@\@height1.3em\@depth0.62em\relax
      \hskip0.9em\relax
      {\small\bfseries Pub\textcolor{pubarxaccentlight}{Arx}}%
      \hskip0.6em\relax
      {\color{pubarxbandmuted}\pubarx@spaced{PREPRINT}}%
      \hfil
      \pubarx@liststart
      \pubarx@ifblank\pubarx@status{}{\pubarx@listitem{\pubarx@status}}%
      \pubarx@ifblank\pubarx@fullid{}{\pubarx@listitem{\pubarx@idlink{\color{white}}}}%
      \pubarx@ifblank\pubarx@license{}{\pubarx@listitem{\pubarx@license}}%
      \hskip0.9em\relax}%
    \nointerlineskip
    \hbox{\colorbox{pubarxnavy}{\box\pubarx@tmpbox}}%
    \nointerlineskip
    {\color{pubarxaccent}\hrule\@height1.1pt}%
  \endgroup}

% Capitals line above the title: the subject, and with nologo also the
% status, identifier and licence that the band would otherwise show.
% (User text is not letterspaced: letterspacing would break -- ligatures.)
\newcommand\pubarx@eyebrow{%
  \pubarx@hasitemsfalse
  \ifpubarx@nologo
    \pubarx@ifblank\pubarx@status{}{\pubarx@hasitemstrue}%
    \pubarx@ifblank\pubarx@fullid{}{\pubarx@hasitemstrue}%
    \pubarx@ifblank\pubarx@license{}{\pubarx@hasitemstrue}%
  \fi
  \pubarx@ifblank\pubarx@subject{}{\pubarx@hasitemstrue}%
  \ifpubarx@hasitems
    {\pubarx@eyebrowfont
     \pubarx@liststart
     \ifpubarx@nologo
       \pubarx@ifblank\pubarx@status{}%
         {\pubarx@listitem{\MakeUppercase{\pubarx@status}}}%
       \pubarx@ifblank\pubarx@fullid{}{\pubarx@listitem{\pubarx@idlink{}}}%
       \pubarx@ifblank\pubarx@license{}%
         {\pubarx@listitem{\MakeUppercase{\pubarx@license}}}%
     \fi
     \pubarx@ifblank\pubarx@subject{}%
       {\pubarx@listitem{\MakeUppercase{\pubarx@subject}}}%
     \par}%
    \vskip5pt\relax
  \fi}

% One author: name, superscript labels and marks, ORCID icon.
\newcommand\pubarx@authorentry[3]{% #1: number, #2: name, #3: labels
  \ifnum#1>\@ne
    \ifnum#1=\pubarx@nauthors\space and \else, \fi
  \fi
  \mbox{#2\pubarx@marks{#1}{#3}\pubarx@orcidicon{#1}}}
\def\pubarx@m{}
\newcommand\pubarx@addmark[1]{%
  \ifx\pubarx@m\@empty
    \def\pubarx@m{#1}%
  \else
    \expandafter\def\expandafter\pubarx@m\expandafter{\pubarx@m,#1}%
  \fi}
\newcommand\pubarx@marks[2]{% #1: author number, #2: affiliation labels
  \begingroup
    \def\pubarx@m{}%
    \if\relax\detokenize{#2}\relax\else\pubarx@addmark{#2}\fi
    \@ifundefined{pubarx@equal@#1}{}{\pubarx@addmark{\pubarx@equalsymbol}}%
    \@ifundefined{pubarx@corr@#1}{}{\pubarx@addmark{\pubarx@corrsymbol}}%
    \ifx\pubarx@m\@empty\else\textsuperscript{\pubarx@m}\fi
  \endgroup}
\newcommand\pubarx@orcidicon[1]{%
  \@ifundefined{pubarx@orcid@#1}{}{%
    \edef\pubarx@tmp{\csname pubarx@orcid@#1\endcsname}%
    \,\expandafter\pubarx@orcidlink\expandafter{\pubarx@tmp}}}

% One affiliation per line, with a hanging superscript label.
\newcommand\pubarx@affentry[2]{%
  \par
  \if\relax\detokenize{#1}\relax
    \noindent
  \else
    \hangindent0.9em\hangafter\@ne
    \noindent\hb@xt@0.9em{\textsuperscript{#1}\hss}%
  \fi
  #2}

% Correspondence and equal-contribution notes.
\newif\ifpubarx@corrfirst
\newcommand\pubarx@correntry[2]{%
  \ifpubarx@corrfirst\pubarx@corrfirstfalse\else; \fi
  #1, \href{mailto:#2}{\nolinkurl{#2}}}
\newcommand\pubarx@notes{%
  \pubarx@hasitemsfalse
  \ifnum\pubarx@ncorr>\z@ \pubarx@hasitemstrue \fi
  \ifpubarx@hasequal \pubarx@hasitemstrue \fi
  \ifpubarx@hasitems
    \par\vskip5pt\relax
    {\pubarx@metafont
     \pubarx@liststart
     \ifnum\pubarx@ncorr>\z@
       \pubarx@listitem{\textsuperscript{\pubarx@corrsymbol}\,Corresponding
         \ifnum\pubarx@ncorr>\@ne authors\else author\fi:\ %
         \pubarx@corrfirsttrue\pubarx@corrlist}%
     \fi
     \ifpubarx@hasequal
       \pubarx@listitem{\textsuperscript{\pubarx@equalsymbol}\,These authors
         contributed equally}%
     \fi
     \par}%
  \fi}

% Received / Revised / Accepted / Posted
\newcommand\pubarx@date[2]{{\bfseries #1}\ #2}
\newcommand\pubarx@datesline{%
  \pubarx@hasitemsfalse
  \pubarx@ifblank\pubarx@received{}{\pubarx@hasitemstrue}%
  \pubarx@ifblank\pubarx@revised{}{\pubarx@hasitemstrue}%
  \pubarx@ifblank\pubarx@accepted{}{\pubarx@hasitemstrue}%
  \pubarx@ifblank\pubarx@posted{}{\pubarx@hasitemstrue}%
  \ifpubarx@hasitems
    \par\vskip2pt\relax
    {\pubarx@metafont
     \pubarx@liststart
     \pubarx@ifblank\pubarx@received{}%
       {\pubarx@listitem{\pubarx@date{Received}{\pubarx@received}}}%
     \pubarx@ifblank\pubarx@revised{}%
       {\pubarx@listitem{\pubarx@date{Revised}{\pubarx@revised}}}%
     \pubarx@ifblank\pubarx@accepted{}%
       {\pubarx@listitem{\pubarx@date{Accepted}{\pubarx@accepted}}}%
     \pubarx@ifblank\pubarx@posted{}%
       {\pubarx@listitem{\pubarx@date{Posted}{\pubarx@posted}}}%
     \par}%
  \fi}

%% ---------------------------------------------------------------------------
%% 16. Abstract, keywords and highlights panels
%%     The abstract and highlights environments go before \maketitle; their
%%     contents are kept in boxes and placed, full width, in the title block.
%% ---------------------------------------------------------------------------
\newcommand\pubarx@panelsetup{%
  \hsize\dimexpr\textwidth-\pubarx@barwidth-2\pubarx@panelpad\relax
  \@parboxrestore
  \linespread{1}\normalfont\normalsize
  \tolerance2000\emergencystretch1.5em\relax
  \parindent\z@}
\newcommand\pubarx@paneltitle[1]{%
  {\noindent\pubarx@labelfont\pubarx@spaced{\MakeUppercase{#1}}\par}%
  \vskip3.5pt\relax}
% \pubarx@panel{tint colour}{bar colour}{vertical material}
\newcommand\pubarx@panel[3]{%
  \par
  \begingroup
    \setbox\pubarx@tmpbox\vbox{\pubarx@panelsetup#3\par}%
    \fboxsep\pubarx@panelpad
    \nointerlineskip
    \hbox{{\color{#2}\vrule\@width\pubarx@barwidth}\colorbox{#1}{\box\pubarx@tmpbox}}%
  \endgroup
  \par}

\newif\ifpubarx@titledone
\newcommand\pubarx@lateheading[1]{%
  \ClassWarning{pubarx}{Place this environment before \string\maketitle\MessageBreak
    so that it appears in the title block}%
  \par\addvspace{\medskipamount}%
  {\noindent\pubarx@labelfont\pubarx@spaced{\MakeUppercase{#1}}\par}%
  \nobreak\vskip2pt\relax\@afterheading}

\renewenvironment{abstract}{%
  \ifpubarx@titledone
    \pubarx@lateheading{\abstractname}\small
  \else
    \global\setbox\pubarx@abstractbox\vbox\bgroup
      \color@begingroup
      \pubarx@panelsetup
      \pubarx@paneltitle{\abstractname}%
      \small\parindent1em\relax
      \noindent
  \fi
  \ignorespaces}
{%
  \ifpubarx@titledone
    \par
  \else
      \par
      \color@endgroup
    \egroup
  \fi}

\newenvironment{highlights}{%
  \ifpubarx@titledone
    \pubarx@lateheading{\highlightsname}\small
  \else
    \global\setbox\pubarx@highlightsbox\vbox\bgroup
      \color@begingroup
      \pubarx@panelsetup
      \pubarx@paneltitle{\highlightsname}%
      \small
  \fi
  \begin{itemize}[leftmargin=1.15em,labelsep=0.5em,topsep=0pt,partopsep=0pt,
    parsep=0pt,itemsep=1.5pt]}
{%
  \end{itemize}%
  \ifpubarx@titledone
    \par
  \else
      \par
      \color@endgroup
    \egroup
  \fi}

\newif\ifpubarx@kwfirst
\newcommand\pubarx@kwsep{%
  \unskip\nobreak\hspace{0.45em}\textcolor{pubarxaccent}{\ensuremath{\cdot}}\hspace{0.45em}}
\newcommand\pubarx@printkeywords{%
  \pubarx@kwfirsttrue
  \@for\pubarx@kw:=\pubarx@keywords\do{%
    \ifx\pubarx@kw\@empty\else
      \ifpubarx@kwfirst\pubarx@kwfirstfalse\else\pubarx@kwsep\fi
      \ignorespaces\pubarx@kw\unskip
    \fi}}
\newcommand\pubarx@keywordline{%
  \par
  {\raggedright\small
   \noindent{\pubarx@labelfont\pubarx@spaced{\MakeUppercase{\keywordsname}}}%
   \hspace{0.8em}\pubarx@printkeywords\par}}

\newcommand\pubarx@abstractpanel{%
  \ifvoid\pubarx@abstractbox
    \pubarx@ifblank\pubarx@keywords{}{%
      \par\vskip12pt\relax
      \pubarx@panel{pubarxtint}{pubarxaccent}{\pubarx@keywordline}}%
  \else
    \par\vskip12pt\relax
    \pubarx@panel{pubarxtint}{pubarxaccent}{%
      \unvbox\pubarx@abstractbox
      \pubarx@ifblank\pubarx@keywords{}{%
        \par\vskip6pt\relax
        {\color{pubarxrule}\hrule}%
        \vskip5pt\relax
        \pubarx@keywordline}}%
  \fi}
\newcommand\pubarx@highlightspanel{%
  \ifvoid\pubarx@highlightsbox\else
    \par\vskip7pt\relax
    \pubarx@panel{pubarxwarm}{pubarxnavy}{\unvbox\pubarx@highlightsbox}%
  \fi}

%% ---------------------------------------------------------------------------
%% 17. \maketitle: the full-width title block on page 1
%% ---------------------------------------------------------------------------
\newcommand\pubarx@titleblock{%
  \begingroup
    \linespread{1}\normalfont\normalsize
    \parindent\z@\parskip\z@\leftskip\z@\rightskip\z@\relax
    \ifpubarx@nologo\else
      \pubarx@band
      \vskip14pt\relax
    \fi
    \pubarx@eyebrow
    {\pubarx@titlefont\pubarx@title\par}%
    \vskip9pt\relax
    {\pubarx@authorfont\pubarx@authors\par}%
    \pubarx@ifblank\pubarx@affiliations{}{%
      \vskip4pt\relax
      {\pubarx@afffont\pubarx@affiliations\par}}%
    \pubarx@notes
    \pubarx@datesline
    \pubarx@abstractpanel
    \pubarx@highlightspanel
    \par
  \endgroup}

% Space between the title block and the body text. In two-column mode LaTeX
% cancels \dbltextfloatsep under the \twocolumn[...] block, so without this
% the first heading would touch the abstract panel.
\newcommand\pubarx@titlesep{\par\vskip18\p@\@plus4\p@\relax}

\newcommand\pubarx@setpdfinfo{%
  \def\pubarx@pdfsubject{PubArx preprint}%
  \pubarx@ifblank\pubarx@fullid{}%
    {\protected@edef\pubarx@pdfsubject{\pubarx@pdfsubject\space PubArx:\pubarx@fullid}}%
  \pubarx@ifblank\pubarx@subject{}%
    {\protected@edef\pubarx@pdfsubject{\pubarx@pdfsubject; \pubarx@subject}}%
  \hypersetup{pdftitle={\pubarx@title},pdfauthor={\pubarx@pdfauthors},
    pdfsubject={\pubarx@pdfsubject},pdfkeywords={\pubarx@keywords}}}

\renewcommand\maketitle{%
  \par
  \pubarx@ifblank\pubarx@title
    {\ClassWarningNoLine{pubarx}{No \string\title\space given}}{}%
  \pubarx@setpdfinfo
  \begingroup
    % \thanks notes use the symbols after * and its dagger, which mark
    % corresponding authors and equal contributions.
    \renewcommand\thefootnote{\@fnsymbol{\numexpr\c@footnote+2\relax}}%
    \def\@makefnmark{\rlap{\@textsuperscript{\normalfont\@thefnmark}}}%
    \long\def\@makefntext##1{\parindent1em\noindent
      \hb@xt@1.8em{\hss\@textsuperscript{\normalfont\@thefnmark}}##1}%
    \if@twocolumn
      \ifnum\col@number=\@ne
        \pubarx@titleblock
        \pubarx@titlesep
      \else
        \twocolumn[\pubarx@titleblock\pubarx@titlesep]%
      \fi
    \else
      \newpage
      \global\@topnum\z@
      \pubarx@titleblock
      \pubarx@titlesep
    \fi
    \thispagestyle{pubarxfirst}\@thanks
  \endgroup
  \global\pubarx@titledonetrue
  \setcounter{footnote}{0}%
  \global\let\thanks\@gobble
  \global\let\@thanks\@empty
  \global\let\maketitle\relax}

%% ---------------------------------------------------------------------------
%% 18. Page styles
%% ---------------------------------------------------------------------------
\newcommand\pubarx@headfont{\normalfont\sffamily\footnotesize\color{pubarxmuted}}
\newcommand\pubarx@pageofpages{Page \thepage\ of \pageref*{LastPage}}
\newcommand\pubarx@headtitle{{\let\\\space\let\newline\space\pubarx@shorttitle}}
\newcommand\pubarx@headid{%
  \pubarx@ifblank\pubarx@fullid
    {\ifpubarx@nologo\else PubArx preprint\fi}%
    {\pubarx@idlink{}}}
\newcommand\pubarx@firstfoot{%
  \textcopyright\ The authors%
  \pubarx@ifblank\pubarx@license{}{\pubarx@listsep Licence: \pubarx@license}}
\newcommand\pubarx@pagestyle{%
  \fancyhf{}%
  \fancyhead[L]{\pubarx@headfont\pubarx@headtitle}%
  \fancyhead[R]{\pubarx@headfont\pubarx@headid}%
  \fancyfoot[L]{\pubarx@headfont\pubarx@runningauthor}%
  \fancyfoot[R]{\pubarx@headfont\pubarx@pageofpages}%
  \renewcommand\headrulewidth{0.4pt}%
  \renewcommand\footrulewidth{0pt}}
\fancypagestyle{pubarx}{\pubarx@pagestyle}
\fancypagestyle{plain}{\pubarx@pagestyle}
\fancypagestyle{pubarxfirst}{%
  \fancyhf{}%
  \fancyfoot[L]{\pubarx@headfont\pubarx@firstfoot}%
  \fancyfoot[R]{\pubarx@headfont\pubarx@pageofpages}%
  \renewcommand\headrulewidth{0pt}%
  \renewcommand\footrulewidth{0pt}}
\renewcommand\headrule{{\color{pubarxrule}%
  \hrule\@height\headrulewidth\@width\headwidth\vskip-\headrulewidth}}
\pagestyle{pubarx}
% fancyhdr fixes \headwidth when the page style is first set (above). Reset
% it once the preamble is done, so that a \geometry{...} in the preamble
% still gives running heads exactly as wide as the text.
\AtBeginDocument{\setlength\headwidth{\textwidth}}

\endinput
%% End of pubarx.cls