# Theme Lab: Tune Family, Preset, and Rhythm

## What Is This Page For?

Use this page to choose a visual direction before you retrofit or create vignettes. You can tune one parameter at a time and immediately see the effect on hierarchy, contrast, and page rhythm.

Start with family and preset, then tune style, then adjust content width. That order gives the fastest path to a coherent page.

## How Do You Use It?

1. Pick a family for color character.
2. Pick a preset for ground/surface mood.
3. Toggle style intensity to set structural emphasis.
4. Adjust content width to match prose density.

    <div class="theme-lab__controls">
      <div>
        <label for="albers-family">Family</label>
        <select id="albers-family" data-albers-control="family">
          <option value="red">red</option>
          <option value="lapis">lapis</option>
          <option value="ochre">ochre</option>
          <option value="teal">teal</option>
          <option value="green">green</option>
          <option value="violet">violet</option>
        </select>
      </div>
      <div>
        <label for="albers-preset">Preset</label>
        <select id="albers-preset" data-albers-control="preset">
          <option value="study">study</option>
          <option value="structural">structural</option>
          <option value="adobe">adobe</option>
          <option value="midnight">midnight</option>
        </select>
      </div>
      <div>
        <label for="albers-style">Style</label>
        <select id="albers-style" data-albers-control="style">
          <option value="minimal">minimal</option>
          <option value="balanced">balanced</option>
          <option value="assertive">assertive</option>
        </select>
      </div>
      <div>
        <label for="albers-width">Content width (ch)</label>
        <input id="albers-width" data-albers-control="width" type="number" min="60" max="100" value="80" />
      </div>
    </div>

    <div class="theme-lab__chips">
      <span class="albers-chip">A900</span>
      <span class="albers-chip">A700</span>
      <span class="albers-chip">A500</span>
      <span class="albers-chip">A300</span>
    </div>
    <p data-albers-lab-summary>family=red | preset=study | style=minimal | width=80ch</p>
    <div class="albers-composition albers-composition--dense" data-seed="theme-lab" data-density="8" aria-hidden="true"></div>

## What Does Each Control Change?

- `family`: accent hue and contrast character for links, rules, and highlights.
- `preset`: background/surface/ink system (light analytical to dark editorial).
- `style`: structural weight (`minimal`, `balanced`, `assertive`).
- `content_width`: reading measure in `ch` units.

## Can You Validate The Palette Quickly?

    pal <- albersdown::albers_palette(params$family)
    stopifnot(
      identical(names(pal), c("A900", "A700", "A500", "A300")),
      all(nzchar(unname(pal)))
    )
    knitr::kable(data.frame(tone = names(pal), hex = unname(pal)), format = "html")

tone | hex
--- | ---
A900 | #C22B23
A700 | #DC3925
A500 | #E44926
A300 | #E35B2D

## Copy Into YAML

    params:
      family: red
      preset: study
      base_size: 13
      content_width: 80
      style: minimal

## Example Plot

    mtcars$grp <- factor(mtcars$cyl)
    stopifnot(length(levels(mtcars$grp)) >= 3)

    ggplot(mtcars, aes(wt, mpg, colour = grp)) +
      geom_point(size = 2.2) +
      labs(
        title = "Theme Lab preview",
        subtitle = "Tune family + preset + style, then copy YAML"
      )