First Steps

This is a guided tour of the building blocks you'll reach for most often. We'll start from an empty file and add one idea at a time, so you can see exactly what each piece does.

The shape of every .tac file

Every Tachyonn file has two parts:

1. A frontmatter block — metadata and styling, fenced by === lines.
2. A body — the actual content of your slides.

Here's a fuller example we'll refer back to:

===
title: Quantum Physics — An Introduction
subtitle: Lecture 1
author: Prof. Ana Souza
date: 2025-06-03
===

# Part I — Foundations

## What is quantum mechanics?

Quantum mechanics describes how matter behaves at the atomic scale.

- Developed between 1900 and 1930
- Planck, Einstein, Bohr, Heisenberg, Schrödinger

## Wave–particle duality

Particles such as electrons behave **both like waves and like particles**.

> Nature isn't just stranger than we imagine — it's stranger than we *can* imagine.
— Richard Feynman

Let's break the pieces down.

The frontmatter

The block between the === fences configures the whole deck. The most common keys are the ones you'd expect:

===
title: My presentation
subtitle: An optional subtitle
author: Your Name
date: 2025-01-15
===

Remember: Tachyonn uses these to generate the cover slide automatically, so you rarely build a title slide by hand. The frontmatter is also where you set colors, fonts, and themes — we'll cover those in the configuration guide.

Creating slides

Section dividers — one #

A single # makes a section slide: a clean divider that announces a new part of your talk.

# Part II — Experiments

By default, section slides don't show a footer — they're meant to feel like a fresh chapter.

Content slides — two ##

Two hashes start an ordinary content slide with a title at the top:

## My slide title

The content goes here.

You can give any slide an ID by adding ::name at the end of its title. IDs let you link to that slide from elsewhere:

## Conclusions ::conclusions

Highlight boxes

A third hash does not start a new slide — it draws a highlight box
inside the current one. Text after ### is the box title (leave it empty for
a box with no title bar), and a <…> modifier picks the style:

## Methodology

### Data collection
How we gathered the data…

###<alert> Caveat
Something to watch out for.

There are three built-in variants — standard, <a>lert and <e>xample. See
Highlight boxes for the
full story.

Formatting your text

Inline formatting is plain Markdown. Here are the ones you'll use constantly:

You type	You get
**bold**	bold
*italic*	italic
***bold italic***	bold italic
~~strikethrough~~	strikethrough
`inline code`	inline code
H_[2]O	subscript (the 2 sits low)
x^[2]	superscript (the 2 sits high)

Subscript and superscript use the bracket form _[...] and ^[...] so they work cleanly even with multi-character content.

Lists

Unordered lists use -, *, or +. Ordered lists use numbers. Indent to nest:

- First idea
- Second idea
  - A supporting point
  - Another one
- Third idea

1. Step one
2. Step two
3. Step three

Images

Insert an image with ![...]. The simplest form is just a path:

![diagram.png]

You can add a caption after a comma, and you can prepend short modifiers in < > to control alignment and size:

![<c> diagram.png, Figure 1: the experimental setup]
![<r, h=200> portrait.png, A right-aligned image, 200px tall]

Common modifiers: <c> centers, <l> aligns left, <r> aligns right, <f> makes it full-width, and <w=N>/<h=N> set the width/height. Need several at once? Put them in one <…> separated by commas — <r, h=200>, not <r><h=200>. Setting just one of width/height keeps the aspect ratio; setting both may distort. Image paths are resolved relative to your .tac file (see Images).

Revealing content step by step

Want content to appear one click at a time? Wrap it in >[n]{…} — it enters on click n. Use <[n]{…} to make something leave. For a whole list, >[]{…} reveals each item in turn:

## Building the argument

This is visible immediately.

>[]{
- This appears on the first click
- This appears on the second click
}

>[3]{And this image lands last.}

The marker wraps any content — a paragraph, an image, a list — and where you put it changes how it behaves. The full story is in Animations.

When you present, each press of → reveals the next step. (And when you export to PDF, each of these reveal states becomes its own page.)

Speaker notes

Anything inside /notes[...] is private — it shows up in presenter mode but never on the audience's screen:

## My slide

The content the audience sees.

/notes[Remember to pause here and ask if there are questions.]

You're ready

That's the core of day-to-day Tachyonn. From here, the Syntax Guide covers everything in depth — layouts, themes, footers, and more.