deckzero

deckzero is an opinionated, CSS-first design system for Reveal.js-style presentations.

It provides:

• a minimal token layer
• a small set of slide layout primitives
• bundled themes plus themeable typography and surface tokens
• a tiny runtime that reads slide hints and applies auto-layout heuristics
• a markdown-first demo workflow that compiles to standard HTML

Package Shape

• dist/deckzero.css: base tokens, rhythm, and primitive styling
• dist/deckzero.js: authoring hint parser and slide hydrator
• dist/themes/light.css: light theme token override
• dist/themes/hulk.css: hulk theme token override
• src/compiler/: markdown compiler and demo build helpers
• demo/src/: canonical markdown demo source
• demo/vendor/: vendored Reveal runtime assets used during demo builds
• demo/dist/: generated browser-runnable demo deck

Package Consumption

deckzero can be consumed as a package directly from its repository.

Example:

{
  "dependencies": {
    "deckzero": "github:nvictor/deckzero"
  }
}

Exposed package entry points:

• deckzero
• deckzero/compiler
• deckzero/deckzero.css
• deckzero/deckzero.js
• deckzero/themes/light.css
• deckzero/themes/hulk.css

Authoring Contract

deckzero remains HTML-based at runtime, but the recommended authoring flow is markdown-first.

The compiler turns markdown into normal Reveal-style <section> markup, and the browser only consumes the generated HTML.

Recommended workflow:

1. Edit demo/src/deck.md.
2. Preserve deckzero hints as HTML comments.
3. Run npm run build.
4. Open demo/dist/index.html.

Use HTML comments inside a slide section:

<!-- layout: split:text-image -->
<!-- accent: warning -->

Supported layout hints:

• title
• statement
• split:text-text
• split:text-image
• split:image-text
• split:image-image
• split:text-image:vertical
• code-focus
• image-caption
• step

These map onto the core layout primitives: title, statement, split, code-focus, image-caption, and step.

Supported pane surface hints:

• <!-- pane-surface: none --> Removes the pane background fill for split layouts while keeping spacing and sizing.

Deck-wide branding can be configured on the .reveal root:

<div
  class="reveal"
  data-dz-brand-src="assets/media/logo.svg"
  data-dz-brand-style="tag"
  data-dz-brand-position="bottom-left"
  data-dz-brand-alt="Acme"
>

• data-dz-brand-src: image URL for the brand asset
• data-dz-brand-style: logo or tag
• data-dz-brand-position: top-left, top-right, bottom-left, or bottom-right
• data-dz-brand-alt: optional accessible label for the image

Brandmark sizing and inset are controlled by tokens in deckzero.css:

:root {
  --dz-brand-inset: clamp(1.5rem, 2.8vw, 2.25rem);
  --dz-brand-width: min(28vw, 15rem);
  --dz-brand-height: min(18vh, 8.5rem);
}

logo mode renders the asset directly. tag mode wraps it in a rounded, bordered treatment for badge-style branding.

For split layouts, use two major content blocks. A common pattern is:

<!-- layout: split:text-image -->
## How It Works

<div>
  <p>Explain the idea.</p>
  <ul>
    <li>One</li>
    <li>Two</li>
  </ul>
</div>

<div>
  <img src="assets/media/default.svg" alt="Preview" />
</div>

If a split slide omits heading or intro blocks and starts directly with the two panes, deckzero treats it as a full-canvas split and lets the panes occupy the full slide height.

If there is no explicit layout hint, deckzero applies simple heuristics:

• heading + paragraph => statement
• code block => code focus
• image + short caption => image caption
• fragments => step
• two top-level content blocks => split text-text

Styling Primitives

Alongside the slide layouts, deckzero also provides low-level styling primitives for repeated within-slide structures.

Card collection

Use .dz-card-grid for repeated card collections:

<div class="dz-card-grid" data-dz-columns="3">
  <div class="dz-card">
    <strong>One</strong>
    <small>Shared shell styling.</small>
  </div>
</div>

Supported column hints:

• data-dz-columns="2"
• data-dz-columns="3"
• data-dz-columns="4"
• data-dz-columns="5"
• omit the attribute for auto-fit card wrapping

Card shell

Use .dz-card for bordered, compact panel content that repeats across a slide.

The shell provides shared padding, radius, surface treatment, and heading rhythm so deck-local CSS does not need to recreate the same panel pattern.

Tone modifiers

Use tone classes to map local meaning onto generic visual treatments:

• .dz-tone-neutral
• .dz-tone-info
• .dz-tone-success
• .dz-tone-warning
• .dz-tone-danger

These work on .dz-card and .dz-sequence-node.

Sequence primitive

Use .dz-sequence and .dz-sequence-node for ordered journeys, reasoning chains, or staged workflows:

<div class="dz-sequence" data-dz-columns="4">
  <article class="dz-sequence-node dz-tone-warning">
    <span class="dz-step-badge">3</span>
    <strong>Decide</strong>
    <small>Pick the next branch.</small>
  </article>
</div>

sequence is intentionally generic enough to cover step chips, numbered paths, and investigation flows without shipping domain-specific class names.

Markdown Compiler

The compiler intentionally allows raw HTML blocks inside markdown for cases where structured slide markup is clearer than inventing a second hint language, especially split panes and custom controls.

Current demo layout:

• source markdown: demo/src/deck.md
• source media: demo/src/assets/media/
• vendored Reveal assets: demo/vendor/reveal/
• generated output: demo/dist/

Compiler code lives in src/compiler/, while scripts/ only provides thin command-line entry points.

Theme Overrides

Theme files should primarily override tokens, while deckzero.css keeps the shared layout system. Bundled themes may also include small, theme-scoped surface overrides for panes and code blocks.

Theme selection example:

<div class="reveal" data-dz-theme="light">

If you want to switch between bundled themes at runtime, load the optional theme stylesheets you plan to toggle to. The dark theme is already covered by the base tokens in deckzero.css.

<link rel="stylesheet" href="assets/deckzero/deckzero.css" />
<link rel="stylesheet" href="assets/deckzero/themes/light.css" />
<link rel="stylesheet" href="assets/deckzero/themes/hulk.css" />
<script src="assets/deckzero/deckzero.js"></script>

The base stylesheet exposes extra themeable typography tokens:

:root {
  --dz-heading: var(--dz-fg);
  --dz-emphasis: var(--dz-fg);
}

Themes can point those at --dz-accent when they want headings and inline emphasis to share the accent color.

The bundled themes currently use those tokens like this:

• dark: headings and emphasis inherit the dark foreground
• light: headings and emphasis inherit the light foreground
• hulk: headings and emphasis use the hulk accent #16b61b

Creating A New Theme

1. Create or update assets/deckzero/themes/<theme>.css with your custom token overrides.
2. Adjust branding-oriented tokens such as accent color, heading color, emphasis color, text color, background color, muted color, --dz-font-sans, and --dz-font-mono.
3. Add scoped surface overrides only when the default pane or code treatments do not fit the theme.
4. Update index.html:
   1. Link to assets/deckzero/themes/<theme>.css.
   2. Set the default .reveal container to data-dz-theme="<theme>".
   3. Add a theme toggle control that can switch between the bundled themes and <theme>.
5. Start from light if you want a bright theme, or from the base dark tokens in deckzero.css if you want a darker direction.

Example theme file:

.reveal[data-dz-theme="<theme>"],
[data-dz-theme="<theme>"] .reveal {
  --dz-bg: #f8fafc;
  --dz-fg: #0f172a;
  --dz-accent: #f97316;
  --dz-muted: #94a3b8;
  --dz-heading: var(--dz-accent);
  --dz-emphasis: var(--dz-accent);
  --dz-font-sans: "Avenir Next", "Segoe UI", sans-serif;
  --dz-font-mono: "JetBrains Mono", ui-monospace, monospace;
}

Hulk-style custom theme recipe

If you want a custom theme that behaves like hulk, start from the light-theme palette, point headings and inline emphasis at your accent, swap in your fonts, and set a default brandmark position on the .reveal root.

Example CSS:

.reveal[data-dz-theme="gamma"],
[data-dz-theme="gamma"] .reveal {
  --dz-bg: #f8fafc;
  --dz-fg: #0f172a;
  --dz-accent: #7c3aed;
  --dz-muted: #64748b;
  --dz-heading: var(--dz-accent);
  --dz-emphasis: var(--dz-accent);
  --dz-font-sans: "Avenir Next", "Segoe UI", sans-serif;
  --dz-font-mono: "JetBrains Mono", ui-monospace, monospace;
  --dz-panel: rgba(255, 255, 255, 0.9);
  --dz-panel-muted: rgba(241, 245, 249, 0.9);
  --dz-shadow: 0 24px 80px rgba(15, 23, 42, 0.12);
}

Example HTML defaults:

<div
  class="reveal"
  data-dz-theme="gamma"
  data-dz-brand-src="assets/media/logo.svg"
  data-dz-brand-style="tag"
  data-dz-brand-position="bottom-left"
  data-dz-brand-alt="Gamma"
>

That setup gives you:

• a light-theme foundation
• accent-colored headers plus b, strong, and em
• custom sans and mono fonts
• a default brandmark placement without changing runtime code

Bundled themes now include:

• dark (default base tokens in deckzero.css)
• light
• hulk with light-theme foundations and accent #16b61b

The generated demo at demo/dist/index.html still defaults to dark; light and hulk are available via the theme toggle.

Runtime

The browser bundle exposes window.Deckzero with:

• apply(root)
• parseBrandPosition(value)
• parseBrandStyle(value)
• parseLayoutHint(value)
• inferLayout(section)

The runtime auto-applies itself on DOMContentLoaded, and again on Reveal's ready and slidechanged events when Reveal is present.

Scripts

• `npm run build`: compile `demo/src/deck.md` into `demo/dist/index.html`, then sync runtime assets
• `npm run sync`: copy `dist/` into `demo/dist/assets/deckzero`
• `npm test`: run runtime and compiler tests

Demo

The demo output includes vendored Reveal runtime assets plus local media, so users do not need to download anything before opening it.

To rebuild the demo:

• `npm run build`

To load the demo:

• Browser: open demo/dist/index.html
• GrandReveal: click Open Deck and choose deckzero/demo/dist or deckzero/demo/dist/index.html