8.3.3 Can you answer these questions?

8.3.3.1 Question about coloring in latex

https://tex.stackexchange.com/landing/r/digest?cta=question&id=629642

Hello from the following code 
\documentclass{article} 
\usepackage{xcolor} 
\usepackage{listings} 
\usepackage{float} 
\usepackage[a4paper,margin=1in,footskip=0.25in]{geometry} 
\colorlet{mygray}{black!30} 
... 
[color] [listings] [code]
 

asked by i`\[Sterling]\274i`\204+-i`\232Degreehttps://tex.stackexchange.com/landing/r/digest?cta=user&id=261122 1 vote

8.3.3.2 Tikz grid with text

https://tex.stackexchange.com/landing/r/digest?cta=question&id=629905

I have a tikz grid with text in beamer. However, it is somehow moved to the left. How can I change it so that it appears centered in the slide? 
Here is the code for the grid: 
\begin{tikzcd} 
... 
[tikz-pgf] [tikz-cd]
 

asked by Rodrigo https://tex.stackexchange.com/landing/r/digest?cta=user&id=92346 1 vote

8.3.3.3 Center proof goal and "QED" below prooftree

https://tex.stackexchange.com/landing/r/digest?cta=question&id=629931

I am using the Clea F. Rees' prooftrees package in order to typeset tableau proofs in LaTeX. Things are working just fine, but there are two caveats I do not know how to deal with. Firstly, the "... 
[alignment] [proof-package] [prooftrees]
 

asked by Vitus SchA~\[Currency]fftlein https://tex.stackexchange.com/landing/r/digest?cta=user&id=242372 1 vote