- 有什么办法可以使小节标题的第一行与 \parident 对齐，而第二行 -- 左对齐？
- 我需要在标题、副标题和副副标题之间设置不同的间距：a. 章节标题和小节标题之间的间距 - 8mm；b. 任何标题和文本之间的间距 - 15mm；c. 文本和小节标题之间的间距 - 1.5 倍行距。
尝试这样做，但没有得到正确的结果：
\documentclass{article}
\usepackage{titlesec}
\usepackage[T1,T2A]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english,russian]{babel}
\titleformat{\section}{\normalfont\fontsize{16}{15}\bfseries\filcenter}{\thesection}{1em}{}
\titleformat{\subsection}{\normalfont\fontsize{14}{15}\bfseries}{\thesubsection}{1em}{}
\titleformat{\subsubsection}{\normalfont\fontsize{14}{15}}{\thesubsubsection}{1em}{}
\titlespacing{\section}{}{10mm}{10mm}
\titlespacing{\subsection}{\parindent}{25mm}{15mm}
\titlespacing{\subsubsection}{\parindent}{25mm}{15mm}
\begin{document}
\section{For three years, car mechanic Paen Long stayed up long after his wife went to bed each night, spending countless hours watching videos on YouTube}
\subsection{For three years, car mechanic Paen Long stayed up long after his wife went to bed each night, spending countless hours watching videos on YouTube}
\subsubsection{For three years, car mechanic Paen Long stayed up long after his wife went to bed each night, spending countless hours watching videos on YouTube}
For three years, car mechanic Paen Long stayed up long after his wife went to bed each night, spending countless hours watching videos on YouTube.
\end{document}
UPD。系统升级（包括 texlive 升级）后，如果我使用 \titleformat，标题中将没有文本。
答案1
章节与子章节之间的间距问题无法自动解决，因为您无法提前知道章节标题后面是一些文本还是子章节标题。所以我认为您必须手动完成。
以下代码是我根据您理解的要求提供的解决方案：
\documentclass{article}
\usepackage[T1]{fontenc}%,T2A
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}%,russian
\usepackage{fourier, erewhon}
\usepackage[aftersep]{titlesec}
\titleformat{\section}{\normalfont\fontsize{16}{15}\bfseries\filcenter}{\thesection}{1em}{}
\titleformat{\subsection}[block]{\normalfont\fontsize{14}{15}\bfseries}{\thesubsection}{1em}{}
\titleformat{\subsubsection}[block]{\normalfont\fontsize{14}{15}}{\thesubsubsection}{1em}{}
\titlespacing{\section}{0pt}{10mm}{10mm}
\titlespacing{\subsection}{0pt}{25mm}{15mm}
\titlespacing{\subsubsection}{0pt}{25mm}{0.5\baselineskip}
\begin{document}
\section{For three years, car mechanic Paen Long stayed up long after his wife went to bed each night, spending countless hours watching videos on YouTube}\vspace{-4ex}
\subsection{For three years, car mechanic Paen Long stayed up long after his wife went to bed each night, spending countless hours watching videos on YouTube}
\subsubsection{For three years, car mechanic Paen Long stayed up long after his wife went to bed each night, spending countless hours watching videos on YouTube}
For three years, car mechanic Paen Long stayed up long after his wife went to bed each night, spending countless hours watching videos on YouTube.
\end{document}
