Widening output from code in rmarkdown html - css

Question

I am trying to display some regression results in an rmarkdown html file. However, the output from the code chunks is too narrow and therefore it is very hard to read the p-values, etc, particularly when I include a floating table of contents. I have tried adjusting options(width = 9999) but this does not seem to fix the issue. I have also tried:
<style>
pre {
overflow-x: auto;
}
pre code {
word-wrap: normal;
white-space: pre;
}
</style>
which allows me to scroll horizontally if needed. However, given I am using regression results, I do not like having to scroll back and forth to read the coefficients and p-values. I have also tried:
<style>
.main-container { width: 1200px; max-width:2800px;}
</style>
adjusting the width and max-width values, to no avail. These solutions are suggested here.
Any idea how I can solve this issue?
Here is an example. Unfortunately I cannot post my regression results, so here is a matrix that essentially replicates the same issue:
---
title: "Untitled"
author: "me"
date: "11/10/2021"
output:
html_document:
toc: true
tow_float: true
---
```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
options(width = 9999)
matrix = matrix(rnorm(100,5,2), ncol = 20)
matrix
However, when I knit the document, I get something like this:
How can I make the output wider?

Answer 1

I found out, where is your problem.
The floating toc is guilty.
Look, I took a code from that post and remove toc_float.
---
title: "R Notebook"
author: "me"
date: "11/10/2021"
output:
html_document:
toc: true
---
<style>
.main-container { width: 1800px; max-width:2800px;}
</style>
## R Markdown
```{r}
options(width = 1500)
dataM <- matrix(rnorm(100, 5, 2), ncol = 20)
dataM
```
And it works:
I think, that this space under toc is reserved. But can't say it with 100% confidence.
An addition
You should make a custom TOC with CSS.
I'm not a pro with CSS, so, I have compiled something for you. You can modify it...
CSS-file:
#TOC {
font-family: Arial, Helvetica, sans-serif;
color:black;
background-color: white;
position: fixed;
top: 0;
left: 0;
width: 150px;
border: 1px solid Black;
padding: 10px;
margin: 30px;
overflow:auto;
}
body {
max-width: 800px;
margin-left:210px;
line-height: 20px;
}
Your header:
---
title: "R Notebook"
author: "me"
date: "11/10/2021"
output:
html_document:
css: TOC.css
toc: true
---