How to align table heading (caption) left wrt table while keeping table itself in center of page?

Question

I was trying to recreate a table from a question with some modifications (irrelevant to the substance in this question). The table which I could build looks like this:

There are still several issues with this table, such as

1. the vertical spacing between cells,
2. the color overflowing the sides and not filling the entire cells.

But in this question, I would like to focus only on the table heading, or caption. I would like to

• align the caption so that it starts where the table starts;
• table should remain in the center of page;
• I would not like to stretch the table heading or caption (so some whitespace should remain in this case to the right of the heading.

Other similar questions generally align both the caption and and to left, that would not work here.

Any ideas of what I should add or modify? Minimally invasive procedures are preferred.

---

\documentclass[12pt]{article}
\usepackage[labelsep=period, tableposition=top, labelfont=bf]{caption}
\usepackage[table]{xcolor} %for cell colour
\usepackage{booktabs}
\usepackage{makecell}
\usepackage{tabu} %for \cellcolor to work inside \rowstyle
\usepackage{siunitx} %for the case when the table had lots of numbers to align (not used here)
\makeatletter\usepackage{microtype}\g@addto@macro@verbatim{\microtypesetup{activate=false}}\makeatother%
\renewcommand\cellalign{cr} %align inside \makecell
\newcolumntype{N}{>{\global\let\currentrowstyle\relax}}
\newcolumntype{O}{>{\currentrowstyle}}
\newcommand{\rowstyle}[1]{\gdef\currentrowstyle{#1}%
  #1\ignorespaces
} %to make entire row boldface/color with one command instead of one at a time
\begin{document}
\begin{table}[!htbp]
    \caption{Title for your table goes here}
    \vspace{-0.5em}
    \centering
    \makebox[\textwidth][c]{\begin{tabular}{@{} Nc|Oc|Oc|Oc|Oc @{}}
        \toprule
        \rowstyle{\bfseries\cellcolor{cyan!70}}
        {Parabola} & {Curve} & {Focus} & {Directrix} & {Vertex}\
        \midrule
        $x^2 = 4py$ & \makecell{up if $p > 0$ \ down if $p < 0$} & $F(0, p)$ & $y = -p$ & $V(0, 0)$\
        \cline{1-5}%horisontal line
        $y^2 = 4px$ & \makecell{right if $p > 0$\ left if $p < 0$} & $F(p, 0)$ & $x = -p$ & $V(0, 0)$\
        \bottomrule
        \end{tabular}}
    \label{table: label for table}
\end{table}
\end{document}

Answer 1

With the help of the threeparttable package and caption's singlelinecheck=false option. (Red lines in the following image indicate the margins and I did not address the various otehr issues with this table.)

\documentclass[12pt]{article}
\usepackage[labelsep=period, tableposition=top, labelfont=bf, singlelinecheck=false]{caption}
\usepackage[table]{xcolor} %for cell colour
\usepackage{booktabs}
\usepackage{makecell}
\usepackage{tabu} %for \cellcolor to work inside \rowstyle
\usepackage{siunitx} %for the case when the table had lots of numbers to align (not used here)
\makeatletter\usepackage{microtype}\g@addto@macro@verbatim{\microtypesetup{activate=false}}\makeatother%
\renewcommand\cellalign{cr} %align inside \makecell
\newcolumntype{N}{>{\global\let\currentrowstyle\relax}}
\newcolumntype{O}{>{\currentrowstyle}}
\newcommand{\rowstyle}[1]{\gdef\currentrowstyle{#1}%
  #1\ignorespaces
} %to make entire row boldface/color with one command instead of one at a time
\usepackage{threeparttable}
\usepackage{showframe}\renewcommand*\ShowFrameColor{\color{red}}
\begin{document}
\begin{table}[!htbp]
\centering
\begin{threeparttable}
    \caption{Title for your table goes here}
    \begin{tabular}{@{} Nc|Oc|Oc|Oc|Oc @{}}
        \toprule
        \rowstyle{\bfseries\cellcolor{cyan!70}}
        {Parabola} & {Curve} & {Focus} & {Directrix} & {Vertex}\
        \midrule
        $x^2 = 4py$ & \makecell{up if $p > 0$ \ down if $p < 0$} & $F(0, p)$ & $y = -p$ & $V(0, 0)$\
        \cline{1-5}%horisontal line
        $y^2 = 4px$ & \makecell{right if $p > 0$\ left if $p < 0$} & $F(p, 0)$ & $x = -p$ & $V(0, 0)$\
        \bottomrule
        \end{tabular}
    \label{table: label for table}
\end{threeparttable}
\end{table}
\end{document}

Answer 2

A possible (partial) solution with the \ttabbox command from floatrow. For the vertical spacing, I replaced the rules from booktabs with thick rules commands from makecell, which do not add any vertical spacing:

\documentclass[12pt]{article}
\usepackage[labelsep=period, tableposition=top, labelfont=bf]{caption}
\usepackage[table]{xcolor} %for cell colour
\usepackage{booktabs}
\usepackage{makecell}
\usepackage{tabu} %for \cellcolor to work inside \rowstyle
\usepackage{siunitx} %for the case when the table had lots of numbers to align (not used here)
\makeatletter\usepackage{microtype}\g@addto@macro@verbatim{\microtypesetup{activate=false}}\makeatother%
\usepackage{floatrow, caption}
\renewcommand\cellalign{cr} %align inside \makecell
\newcolumntype{N}{>{\global\let\currentrowstyle\relax}}
\newcolumntype{O}{>{\currentrowstyle}}
\newcommand{\rowstyle}[1]{\gdef\currentrowstyle{#1}%
  #1\ignorespaces
} %to make entire row boldface/color with one command instead of one at a time
\usepackage{lipsum}
\begin{document}
\lipsum[11]
\begin{table}[!htbp]
\captionsetup{singlelinecheck=false}\setlength{\extrarowheight}{2ex}
    \centering
    \ttabbox{\begin{tabular}{@{} Nc|Oc|Oc|Oc|Oc @{}}
        \Xhline{0.08em}
        \rowstyle{\bfseries\cellcolor{cyan!70}}
        {Parabola} & {Curve} & {Focus} & {Directrix} & {Vertex}\[1.5ex]
        \Xhline{0.05em}
        $x² = 4py$ & \makecell{up if $p > 0$ \ down if $p < 0$} & $F(0, p)$ & $y = -p$ & $V(0, 0)$\[1.5ex]
        \cline{1-5}%horizontal line
        $y² = 4px$ & \makecell{right if $p > 0$\ left if $p < 0$} & $F(p, 0)$ & $x = -p$ & $V(0, 0)$\[1.5ex]
        \Xhline{0.08em}
        \end{tabular}}{%
    \caption{A very very long title for your table goes here and nowhere else. }
    \label{table: label for table}}
\end{table}
\end{document}