修改 LyX 中标签和内容之间的缩进

Question

我有以下列表，使用 LyX 中的“标签”列表样式创建：

每当按下标签上的空格键或制表键时，LyX 似乎都会自动添加一个大的缩进（例如在“AB1”和“Test”之间）。

LyX 导出以下 LaTeX 代码：

%% LyX 2.3.5-1 created this file.  For more info, see http://www.lyx.org/.
%% Do not edit unless you really know what you are doing.
\documentclass[oneside,english]{amsart}
\usepackage[T1]{fontenc}
\usepackage[latin9]{inputenc}
\usepackage[a4paper]{geometry}

\usepackage{amsthm}

\makeatletter
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Textclass specific LaTeX commands.
\numberwithin{equation}{section}
\numberwithin{figure}{section}
\newenvironment{lyxlist}[1]
    {\begin{list}{}
        {\settowidth{\labelwidth}{#1}
         \setlength{\leftmargin}{\labelwidth}
         \addtolength{\leftmargin}{\labelsep}
         \renewcommand{\makelabel}[1]{##1\hfil}}}
    {\end{list}}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% User specified LaTeX commands.
\usepackage[T1]{fontenc}
\usepackage{lmodern}

\makeatother

\usepackage{babel}
\begin{document}
\begin{lyxlist}{00.00.0000}
\item [{AB1.}] Test
\begin{lyxlist}{00.00.0000}
\item [{a)}] Test
\end{lyxlist}
\item [{AC2.}] Test
\end{lyxlist}

\end{document}

我怎样才能减少这个缩进的长度？