定理环境

清平乐·六盘山_百度汉语
作者：毛 泽 东
天高云淡，
望断南飞雁。
不到长城非好汉，
屈指行程二万。
六盘山上高峰，
红旗漫卷西风。
今日长缨在手，
何时缚住苍龙？

书愤五首·其一
宋 · 陆游
早岁那知世事艰，中原北望气如山。楼船夜雪瓜洲渡，铁马秋风大散关。塞上长城空自许，镜中衰鬓已先斑。出师一表真名世，千载谁堪伯仲间。

documentclass[UTF8]{ctexart}
usepackage{enumitem}
usepackage{tcolorbox}
cbuselibrary{many}
% cbuselibrary{skins, breakable, theorems}

usepackage{amsmath, amssymb}

ewtcbtheorem{question}{题~(理}%
{enhanced, breakable,
colback = white, colframe = cyan, colbacktitle = cyan,
attach boxed title to top left = {yshift = -2mm, xshift = 5mm},
boxed title style = {sharp corners},
fonttitle = sffamilyfseries, separator sign = {).~}}{qst}

egin{document}
section{测试}

egin{question}{函数}{example}
已知函数 $ f(x) = (x - 2)mathrm{e}^{2} + a (x - 1)^{2} $ 有两个零点.
egin{enumerate}[label=(arabic*)]
item 求 $ a $ 的取值范围;
item 设 $ x_{1} $, $ x_{2} $ 是 $ f(x) $ 的两个零点，证明 $ x_{1} + x_{2} < 2 $.
end{enumerate}
end{question}

section{标题}
ewtcbtheorem[number within=section]{mytheo}{定理}%
{colback=green!5,colframe=green!35!black,fonttitle=fseries}{th}
egin{mytheo}{我的定理}{}
这是默认样式。
end{mytheo}
egin{mytheo}[separator sign = { $lacktriangleright$}]{我的定理}{}
分隔符修改为 $lacktriangleright$。
end{mytheo}
egin{mytheo}[description delimiters parenthesis]{我的定理}{}
定界符修改为圆括号。
end{mytheo}
egin{mytheo}[description color=red!25!yellow,
description font= {mdseriesitshape}]{我的定理}{}
标题的字体及颜色修改。
end{mytheo}
egin{mytheo}[terminator sign={.}]{我的定理}{}
标题后的终止符。
end{mytheo}

cbset{boxrule = 0.5mm, colback=red!5!white, colframe=red!75!black,
title = {My title}}
egin{tcolorbox}
This is a extbf{tcolorbox}.
end{tcolorbox}
egin{tcolorbox}[toprule = 3mm]
This is a extbf{tcolorbox}.
end{tcolorbox}
egin{tcolorbox}[bottomrule = 3mm]
This is a extbf{tcolorbox}.
end{tcolorbox}
egin{tcolorbox}[leftrule = 3mm]
This is a extbf{tcolorbox}.
end{tcolorbox}
egin{tcolorbox}[rightrule = 3mm]
This is a extbf{tcolorbox}.
end{tcolorbox}
egin{tcolorbox}[titlerule = 3mm]
This is a extbf{tcolorbox}.
end{tcolorbox}

cbset{colback = red!5!white, colframe = red!75!black}
egin{tcolorbox}[arc = 0mm]
This is a extbf{tcolorbox}.
end{tcolorbox}
egin{tcolorbox}[arc = 3mm]
This is a extbf{tcolorbox}.
end{tcolorbox}
egin{tcolorbox}[arc = 4mm, outer arc = 1mm]
This is a extbf{tcolorbox}.
end{tcolorbox}
egin{tcolorbox}[arc = 1mm, outer arc = 4mm]
This is a extbf{tcolorbox}.
end{tcolorbox}

end{document}

documentclass{article}
usepackage{tcolorbox}
cbuselibrary{most}
egin{document}
cbset{colback = red!5!white, colframe = red!75!black}
egin{tcolorbox}[arc = 0mm]
This is a extbf{tcolorbox}.
end{tcolorbox}
egin{tcolorbox}[arc = 3mm]
This is a extbf{tcolorbox}.
end{tcolorbox}
egin{tcolorbox}[arc = 4mm, outer arc = 1mm]
This is a extbf{tcolorbox}.
end{tcolorbox}
egin{tcolorbox}[arc = 1mm, outer arc = 4mm]
This is a extbf{tcolorbox}.
end{tcolorbox}
end{document}

%%https://liam.page/categories/LaTeX/