How can I improve the drawing of Thomae's function?

Question

I 'm trying to draw Thomae's function (in black). I want the plot below.

I used marmot's code from here.

\documentclass[tikz,border=3.14mm]{standalone}
\begin{document}
\begin{tikzpicture}[scale=8]
\draw [-stealth] (-0.1,0) -- (1.1,0);
\draw [-stealth] (0,-0.1) -- (0,0.6);
\foreach \X in {1,...,7}
{\ifnum\X=1
\else
\draw (0.02,1/\X) -- (-0.02,1/\X) node[left,xshift={(-(1+pow(-1,\X)))*3pt}]{$\frac{1}{\X}$};
\fi
}
\foreach \X [evaluate=\X as \Ymax using {int(\X-1)}]in {25,24,...,2}
{\foreach \Y in {1,...,\Ymax}
 {\ifnum\X<6
 \draw (\Y/\X,0.02) -- (\Y/\X,-0.02) node[below,fill=white]{$\frac{\Y}{\X}$};
 \else
 \draw[ultra thin] (\Y/\X,0.01) -- (\Y/\X,-0.01);
 \fi
 \pgfmathtruncatemacro{\TST}{gcd(\X,\Y)}
 \ifnum\TST=1
 \fill ({\Y/\X},1/\X) circle(0.2pt); 
 \fi
 }
}
\foreach \X in {0,1,...,80}
{\fill (\X/80,0) circle(0.2pt); }
\end{tikzpicture}
\end{document}

But I have 3 problems:

1. I prefer the image to have more details, as the one I saw you.
2. I don't want the space between x-dots and upper-dots.

3. If I use this code, I get an other (flat) image, than this I expected.

• Is there any solutions for 1 and 2?
• If it's not, what should I do with 3?

Thanks in advanced!