Tweaks

Tweaks Skill · 参数化变体面板

Wrap any HTML artifact with a side panel of live controls that rewrite CSS custom properties in real time and persist to localStorage. Inspired by the huashu-design tweak pattern.

What you produce

A single self-contained HTML file with two layers:

1. Stage — the original artifact (landing page / deck / dashboard)

re-keyed so all visual decisions read from CSS custom properties: --accent, --scale, --density, --mode, --motion.

1. Panel — a fixed sidebar (or drawer on small viewports) with

form controls bound to those custom properties via a tiny vanilla-JS bridge. Persists every change to localStorage keyed by the artifact identifier.

The user can:

• Open the artifact and see the stage rendered with their saved

preferences (or sensible defaults).

• Adjust accent / scale / density / mode / motion in the panel and

watch the stage update instantly — no rerender.

• Press T to hide / reveal the panel; R to

reset to defaults.

• Refresh the page — every choice is persisted.

When to use

• The user generated something they like 80% of, and wants to dial

in the last 20% themselves.

• You're presenting a design system / brand and want the audience to

feel the variants live (instead of you re-running the agent).

• You're shipping a stand-alone demo (e.g. a portfolio piece) and

want viewers to play.

When not to use

• One-shot artifacts that won't be iterated on (e.g. a runbook —

parameters don't help).

• When the artifact's value is in fixed ratios (e.g. an infographic

with carefully balanced data viz — knobs would degrade it).

The 5 standard knobs

> Pick a subset that suits the artifact. Don't ship all 5 if only 2 > matter — clutter is a regression.

1. --accent — Accent color

A select with 5–8 curated swatches (don't ship a free color picker — the user will pick a bad color and blame you).

const ACCENT_PRESETS = [
  { id: 'rust',    val: '#c96442', label: 'Rust' },
  { id: 'cobalt',  val: '#2c4d8e', label: 'Cobalt' },
  { id: 'sage',    val: '#4a7a3f', label: 'Sage' },
  { id: 'plum',    val: '#7a3f6a', label: 'Plum' },
  { id: 'graphite',val: '#3a3a3a', label: 'Graphite' },
];

The artifact uses var(--accent) everywhere it had a hard-coded accent before. Border / link / pull-quote rule / CTA all flip together.

2. --scale — Type scale (0.85 / 1.0 / 1.15)

Three settings: Compact (0.85), Normal (1.0), Generous (1.15). All font-size declarations multiply by var(--scale) via calc(... * var(--scale)).

Don't go beyond ±15% — beyond that the layout breaks (column flow, breakpoints, line counts).

3. --density — Layout density (Tight / Normal / Roomy)

Three settings that swap the spacing scale: Tight (0.75) / Normal (1.0) / Roomy (1.4). All padding / gap / margin declarations multiply by var(--density).

This is the highest-impact knob — it's also the most fragile, so every layout-critical container must declare its base spacing in custom properties before you wrap.

4. --mode — Light / Dark

A 2-state toggle. Sets data-mode="light" vs "dark" on the ` element and the artifact's :root` selector responds with two color sets.

If the artifact already has a media-query-based dark mode, replace it with the data-attr version — the user's choice should win over their OS.

5. --motion — Off / Subtle / Lively

Three settings. Maps to a CSS variable --motion-mult that scales all transition-duration / animation-duration declarations:

• Off — 0s (also disables WebGL canvases / decorative animation).
• Subtle — 1.0 (the artifact's authored timing).
• Lively — 1.6 (slower transitions, more visible motion).

Respect prefers-reduced-motion: default to Off if the user has that set, regardless of stored preference.

Implementation primitives

Read assets/wrap.html — it ships the panel + bridge as an inert template. Your job is to:

1. Take the user's existing artifact HTML.
2. Lift its accent / mode / spacing / scale into custom properties

(search for hard-coded #hex / Npx / Nrem and convert).

1. Paste the contents into the marked region of wrap.html.
2. Edit assets/wrap.html's KNOBS array to keep only the knobs

you decided are relevant to this artifact. Don't ship 5 if 2 matter.

1. Patch the STORAGE_KEY to a unique slug (tweaks-).

The bridge in wrap.html:

• Loads localStorage[STORAGE_KEY] JSON on first paint.
• Applies values as document.documentElement.style.setProperty('--accent', ...).
• Listens to every form control's change event and writes back.
• Exposes T (toggle panel) and R (reset).

Workflow

Step 1 — Acquire the artifact

Same options as the critique skill:

1. Project file (index.html in the project folder).
2. Pasted HTML in the chat.
3. Generated by you in this turn.

Step 2 — Decide which knobs apply

Read the artifact's CSS first. For each knob, decide yes / no:

• --accent — yes if the artifact has 1 accent color used ≥ 3 times.
• --scale — yes if the artifact is type-driven (article, deck,

pricing page).

• --density — yes if the artifact has consistent gap / padding

rhythm (deck, dashboard, landing). No for runbooks (already dense).

• --mode — yes if the artifact has authored dark mode tokens, or

you're willing to derive them.

• --motion — yes if the artifact has any transition / animation

worth scaling. No for static reports / critique reports.

Default: 3 knobs is the sweet spot. Five is too busy, one is not worth a panel.

Step 3 — Lift hard-coded values into custom properties

Open assets/wrap.html's ` block — copy its custom-property naming scheme (--accent, --scale`, etc.). In the user's artifact, find every place those concerns live and rewrite:

• color: #c96442 → color: var(--accent)
• font-size: 18px → font-size: calc(18px * var(--scale))
• padding: 24px 32px → padding: calc(24px * var(--density)) calc(32px * var(--density))
• transition: opacity 200ms → transition: opacity calc(200ms * var(--motion-mult))

If the artifact uses clamp() or vw already, multiply the outer value by the custom property — don't tear apart clamp(...).

Step 4 — Paste into the wrap

Copy the artifact's ` and into the marked regions of wrap.html`. Keep the panel + bridge intact.

Step 5 — Test the loop

Open the result, click each knob at least once, refresh the page, confirm the choice persists. If a knob breaks the layout — remove it, don't ship it.

Output contract

" type="text/html" title=" · Tweaks">

...

One sentence before the artifact ("Wrapped X with a 3-knob tweak panel — accent / scale / mode."). Stop after ``.

Hard rules

• Don't ship a free color picker — only curated swatches. Users

pick bad colors when given freedom; saving them from that is the whole point.

• Persist by artifact identifier — tweaks-, not a global

key. Two artifacts open in two tabs must not share state.

• Respect prefers-reduced-motion — default to Off for motion

if the user has that set, override only on explicit click.

• Single-file — no external CSS / JS / fonts beyond the artifact's

existing imports. Inline the panel + bridge.

• Panel hidden by default on viewports < 720px — slide-in drawer

via a "T" button at top-right.

• Don't ship more than 5 knobs. Three is the sweet spot.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: nexu-io
• Source: nexu-io/open-design
• License: Apache-2.0
• Homepage: https://open-design.ai

Install and usage instructions live in the source repository linked above.