将 tcolorbox 的角弄圆

Question

代码来自这很好的答案，我该如何修改它以使所有框架都变成圆角？我设法将主框架弄圆了，但其他两个仍然是直的：

\documentclass{article}
\usepackage[many]{tcolorbox}
\usepackage{lipsum}
% --

\tcbset{
    titlecommon/.style={
        fontupper=\Large\bfseries\sffamily,
        top=2mm,
        bottom=2mm,
        halign=center,
        sharp corners,
        leftrule=0.5mm, %to draw left side in subtitle box
        rightrule=0.5mm, %to draw right side in subtitle box
        opacityfill=.5,  %to test subtitles geometry and positioning
    },
    toptitle/.style={
        titlecommon,
        colframe=green,
        colback=green!20,
    },
    bottomtitle/.style={
        titlecommon,
        colframe=red,
        colback=red!20,
    },
}   

\newtcolorbox{twotitle}[3][]{
    enhanced,
    arc=5pt,
    % sharp corners,
    colback=white,
    colframe=black!75,
    notitle,
    before upper={\tcbsubtitle[toptitle]{#2}},
    after upper={\tcbsubtitle[bottomtitle]{#3}},
    top=-1.5mm, %-boxsep-toprule
    bottom=-1.5mm, %-boxsep-bottomrule
    #1,
}

\begin{document}
\begin{twotitle}[colback=orange!20]{Title}{Test}
\lipsum[1]
\end{twotitle}
\end{document}

Answer 1

经过一些调整

\documentclass{article}
\usepackage[many]{tcolorbox}
\usepackage{lipsum}
% --

\tcbset{
    titlecommon/.style={
        fontupper=\Large\bfseries\sffamily,
        top=2mm,
        bottom=2mm,
        halign=center,
        sharp corners,
        leftrule=0.5mm, %to draw left side in subtitle box
        rightrule=0.5mm, %to draw right side in subtitle box
        opacityfill=1,  %to test subtitles geometry and positioning
        arc=5pt,
    },
    toptitle/.style={
        titlecommon,
        colframe=green,
        colback=green!20,
        rounded corners=north,
    },
    bottomtitle/.style={
        titlecommon,
        colframe=red,
        colback=red!20,
        rounded corners=south,
    },
}   

\newtcolorbox{twotitle}[3][]{
    arc=5pt,
    enhanced,
    % sharp corners,
    colback=white,
    colframe=black!75,
    notitle,
    before upper={\tcbsubtitle[toptitle]{#2}},
    after upper={\tcbsubtitle[bottomtitle]{#3}},
    top=-1.5mm, %-boxsep-toprule
    bottom=-1.5mm, %-boxsep-bottomrule
    #1,
}

\begin{document}
\begin{twotitle}[colback=orange!20]{Title}{Test}
\lipsum[1]
\end{twotitle}
\end{document}