tcolorbox 自定义标题框样式

Question

有人能写出代码来获得与框标题相似的形状吗？画得笨拙的线是为了显示没有角点的形状。标题框必须看起来像大框里面的圆形框，稍微向上推。大框四周都有橡胶保护。它们两个都必须看起来像一块。框的背景颜色可以是白色。有点像底部示例的标题样式，tcolorbox 手册 4.30 第 165 页。

更新 这是另一个例子。实际上填充颜色经常被用来隐藏东西。

Answer 1

或多或少：

\documentclass{article}
\usepackage[most]{tcolorbox}
\usepackage{varwidth}
\usepackage{lipsum}

\newtcolorbox{mybox}[2][]{enhanced, interior hidden,
colframe=cyan!30, colback=cyan!30, coltitle=blue!70!black,
fonttitle=\bfseries\sffamily,
attach boxed title to top left,
boxed title style={empty, boxrule=0.5mm},
varwidth boxed title=0.5\linewidth,
underlay boxed title={
\path[draw=cyan!30, line width=0.5mm, rounded corners, fill=cyan!30]
([xshift=.25mm]frame.west) |- ([xshift=-2.5mm]title.north east) to[out=0, in=180] ([xshift=7.5mm, yshift=-.25mm]title.south east);  
},
title={#2},#1}
\begin{document}

\begin{mybox}{My title}
\lipsum[2]
\end{mybox}

\begin{mybox}{A longer title}
\lipsum[2]
\end{mybox}

\end{document}

更新：白色背景和下方标题

\documentclass{article}
\usepackage[most]{tcolorbox}
\usepackage{varwidth}
\usepackage{lipsum}

\newtcolorbox{mybox}[2][]{empty, 
coltitle=black,
fonttitle=\bfseries\sffamily,
attach boxed title to top left={yshift=-2.5mm},
boxed title style={empty, size=small, top=1mm, bottom=0pt},
varwidth boxed title=0.5\linewidth,
frame code={
\path (title.east|-frame.north) coordinate (aux);
\path[draw=black, line width=0.5mm, rounded corners]
(frame.west) |- ([xshift=-2.5mm]title.north east) to[out=0, in=180] ([xshift=7.5mm]aux)-|(frame.east)|-(frame.south)-|cycle;  
},
title={#2},#1}
\begin{document}

\begin{mybox}{My title}
\lipsum[2]
\end{mybox}

\begin{mybox}{A longer title}
\lipsum[2]
\end{mybox}

\end{document}