Footer

The footer is the strip along the bottom of each slide. It's a natural home for page numbers, your name, the talk's title, or a logo. Tachyonn gives you three independent slots — left, center, and right — and each can hold text or an image.

The basics

Set each slot in the deck frontmatter:

===
footer.left:   {author}
footer.center: {title}
footer.right:  {page} / {total}
===

You only set the slots you want. Leaving footer.center out simply means the center stays empty.

Text variables

Footer text can include variables in curly braces, which Tachyonn fills in for each slide:

Variable	What it becomes
{page}	The current slide number (starting at 1)
{total}	The total number of slides
{title}	The deck title
{subtitle}	The deck subtitle
{author}	The author
{date}	The date from the frontmatter
{description}	The description from the frontmatter

You can mix plain text and variables freely:

===
footer.left:  {author} — {date}
footer.right: Slide {page} of {total}
===

Using an image

To put an image in a slot — a university crest or a company logo, say — use the ![path] form:

===
footer.left:  ![university.png]
footer.right: {page} / {total}
===

Footer images resolve exactly like any other image: a
bare filename (![university.png]) is looked up in your img/ folder first and
then beside the .tac file, while a relative or absolute path
(![assets/university.png]) resolves as written.

The same image modifiers apply too, so you can size the logo right in the slot:

===
footer.left: ![<h=20> university.png]
===

By default a footer image is capped to the footer's height; <w=N>/<h=N> let
you fine-tune it.

Which slides show the footer?

A footer on a title or section slide usually looks out of place, so Tachyonn picks sensible defaults per layout. These defaults come from the active theme:

Layout	Footer by default
title (cover)	Hidden
section (divider)	Hidden
media	Hidden
big-number	Hidden
quote	Shown
standard	Shown
two-column	Shown
three-column	Shown
grid	Shown
code-window	Shown
image-and-text	Shown

Overriding for one slide

Need to break the default on a specific slide? Set footer in that slide's frontmatter:

## A slide with no footer
===
footer: false
===

Content.

# A section that *does* show the footer
===
footer: true
===

A per-slide setting always wins over the layout default.

Overriding a slot's content

You can also override an individual slot on one slide — the same
footer.left / footer.center / footer.right keys work in a per-slide ===.
Only the slots you set change; the others still inherit the deck's footer. This
is handy when a dark slide needs a light logo, for instance:

## A dark slide
===
background: #14141c
color: #eee
footer.right: ![<h=22> logo-white.png]
===

Styling the footer

Three friendly keys cover the usual cases — put them in the deck frontmatter, in a tac.config or in a .tt theme:

===
footerFont: JetBrains Mono, monospace
footerSize: 12px
footerColor: #8a8f98
===

footerFont is the footer's own typeface; leave it out and the footer simply uses the deck's body font, as it always did.

Under those keys are CSS custom properties, which you can also set directly:

CSS variable	Friendly key	Default	Controls
--tac-footer-font	footerFont	(the deck font)	Typeface
--tac-footer-size	footerSize	13px	Font size
--tac-footer-color	footerColor	var(--tac-text-muted)	Text color
--tac-footer-height	—	32px	Footer height
--tac-footer-padding	—	28px	Left/right padding