OK, so the cybertron theme has some issues where it is preventing Obsidian from loading other snippets. I’ll save you the boring details, but I’ll suggest edits to the author. Then you should be good to go to load snippets.
On the side of your snippets, you shouldn’t need much to pull the headings out to the side. If you wanted to change color, font size, etc you can add those in. Also if you want to hide the collapse arrows you can do that for only the H6 ones while leaving the others alone, you can do that with the following:
div.markdown-preview-view h6 {
position: relative;
left: -3%;
line-height: 0px;
font-size: 10px;
margin: 0px 0px -10px 0px;
color: var(--text-faint);
}
div.markdown-preview-view h6 div.heading-collapse-indicator {
visibility: hidden;
}