Remove indentation from enumerate

Question

new to this forum but have found many solutions to my problems in the past.

I would like to format a list in the style shown in the first image.

I believe the solution is somewhere in the enumitem package but I can't figure it out. I've got the nested lists and the label names, its the alignment of the label inline with the main text and the alignment of the item body that I can't do.

Edit:

Here is what I have tried,

\usepackage{enumitem}
\setenumerate[1]{label=\arabic*}
\setenumerate[2]{label*=.\arabic*}
\setenumerate[3]{label*=.\arabic*}
\setenumerate{align=right}
\setenumerate{leftmargin = 0pt}

And it results in this

Edit 2: Zarko's suggestion gives me this

I'm a fan of the first level label aligning with the section label but I would like to remove the indent from the subsequent levels.

Edit 3:

My modification to Zarko's code.

\documentclass[12pt]{article}
\linespread{1.3}
\usepackage[a4paper,portrait,margin = 2.5cm]{geometry}
\usepackage[justification=centering]{caption}

\usepackage{enumitem}
\setenumerate[1]{label=\arabic*}
\setenumerate[2]{label*=.\arabic*}
\setenumerate[3]{label*=.\arabic*}
\setenumerate{align=right}
\setenumerate{leftmargin =*}
\begin{document}

\section{Section One}
Some text
\begin{enumerate}
\item Relevant standards - ClimbTrack shall be designed to conform with relevant international and national standards where possible however for the sake of brevity they are excluded from this document. 
\item Functional Properties 
\begin{enumerate}
\item ClimbTrack shall have a means for measuring the movement speed of the users hands and feet (extremities).
\begin{enumerate}
\item ClimbTrack shall be capable of measuring extremity speeds between 0 and 15m/s. (https://www.sciencedirect.com/science/article/pii/S1877705815014897)
\item The movement speed of users extremities shall be measured to a resolution of +- 0.05m/s. 
\end{enumerate}
\end{enumerate}
\end{enumerate}

\end{document}

Answer 1

I think this does what you want:

\documentclass[11pt]{article}
\usepackage[utf8]{inputenc}
\usepackage{fourier}
\usepackage[a4paper, margin = 2.5cm, showframe]{geometry}
\usepackage{url}
\def\UrlFont{\sffamily}

\usepackage{enumitem}
\setenumerate[1]{wide = 0pt,labelwidth = 1.25cm, leftmargin =!, label=\arabic*}
\setenumerate[2]{labelwidth =1.25cm, align = left, leftmargin =0cm, label*=\arabic*}
\setenumerate[3]{labelwidth =1.25cm, align = left, leftmargin =0cm, label*=.\arabic*}


\begin{document}

\section{Section One}
Some text
\begin{enumerate}
    \item Relevant standards - ClimbTrack shall be designed to conform with relevant international and national standards where possible however for the sake of brevity they are excluded from this document.
    \item Functional Properties.
    \begin{enumerate}
        \item ClimbTrack shall have a means for measuring the movement speed of the users hands and feet (extremities).
        \begin{enumerate}
            \item ClimbTrack shall be capable of measuring extremity speeds between 0 and 15\,m/s. (\url{https://www.sciencedirect.com/science/article/pii/S1877705815014897}).
            \item The movement speed of users extremities shall be measured to a resolution of $\pm 0.05 $\,m/s.
        \end{enumerate}
    \end{enumerate}
\end{enumerate}

\end{document} 

Answer 2

I propose this solution

\documentclass[12pt]{article}
\usepackage[a4paper,portrait,margin = 2.5cm]{geometry}

\usepackage{enumitem}
\setlist[enumerate]{font=\sffamily\bfseries, label*=\arabic*., leftmargin=1.5cm, labelwidth=1.25cm, align=left} 
\setlist[enumerate,2]{leftmargin=0cm}
\setlist[enumerate,3]{leftmargin=0cm}

\begin{document}

\section{Section One}
Some text
\begin{enumerate}
    \item Relevant standards - ClimbTrack shall be designed to conform with relevant international and national standards where possible however for the sake of brevity they are excluded from this document. 
    \item Functional Properties 
    \begin{enumerate}
        \item ClimbTrack shall have a means for measuring the movement speed of the users hands and feet (extremities).
        \begin{enumerate}
            \item ClimbTrack shall be capable of measuring extremity speeds between 0 and 15m/s. (https://www.sciencedirect.com/science/article/pii/S1877705815014897)
            \item The movement speed of users extremities shall be measured to a resolution of +- 0.05m/s. 
        \end{enumerate}
    \end{enumerate}
\end{enumerate}
\end{document}

Answer 3

edit: after your edit of question become clear that you look for simple solution for nesting of lists. my first suggestion doesn't anticipate this, so it can't solve your problem.

meanwhile you receive solution for nested list, so i can now show only slightly different solution:

\documentclass{article}
\usepackage{enumitem}
\setlist[enumerate]{label*=\arabic*.,
                    labelwidth=6ex,
                    labelsep=2ex,
                    leftmargin=\dimexpr\labelwidth+\labelsep\relax,
                    align=left}
\setlist[enumerate,2]{leftmargin=0pt}
\setlist[enumerate,3]{leftmargin=0pt}
\usepackage{url}

\begin{document}
\section{section}
\subsection{subsection}
Some text
    \begin{enumerate}
\item Relevant standards - ClimbTrack shall be designed to conform with relevant international and national standards where possible however for the sake of brevity they are excluded from this document.
\item Functional Properties
        \begin{enumerate}
    \item ClimbTrack shall have a means for measuring the movement speed of the users hands and feet (extremities).
            \begin{enumerate}
        \item ClimbTrack shall be capable of measuring extremity speeds between \SI{0}{m/s} and {15}{m/s}. (\url{https://www.sciencedirect.com/science/article/pii/S1877705815014897})
        \item The movement speed of users extremities shall be measured to a resolution of \SI{\pm 0.05}{m/s}.
            \end{enumerate}
        \end{enumerate}
    \end{enumerate}
 \end{document}