Supermarket Sign Painter demo
Supermarket Sign Painter

A vibrant aesthetic inspired by Brazilian supermarket hand-painted signs, featuring bold hand-lettered typography, bright promotional colors, and playful sale-tag graphics.
Category: Retro & Pop
Era: 1980s Retro
Prompt: 17.9 KB · 2476 words
# SYSTEM PROMPT — CODING TASK: "CARTAZISTA DE SUPERMERCADO" LANDING PAGE

**Role:** Act as a Senior Frontend Engineer and Expert UI Designer. Build the complete, production-ready landing page described below in a single first attempt — no stubs, no "to be implemented" comments, no lorem ipsum.

**Product Concept:** A landing page for a fictional hand-painted retail poster studio ("cartazista") that produces Brazilian supermarket-style promotional posters for stores and markets. The visual language is retro-pop vernacular retail art: dense informative layouts, garrafais (oversized bottle-shaped) lettering, fluorescent inks, price ribbons, crepe-tape strips, atomic-marker strokes, and paper-textured poster backgrounds. All user-facing copy must be written in **English**, in a loud, retail-promotional voice (translate any Portuguese terms from the source spec: "OFERTA" → "SALE", "PREÇO" → "PRICE", "fitas crepon" → "crepe tape", "letras garrafais" → "garrafais lettering").

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## 1. STRICT RULES & ARCHITECTURE

**1.1 CSS-First Architecture & Zero Inline CSS**
* **No Inline CSS:** The `style="..."` attribute is forbidden anywhere in the HTML. No `<style>` blocks in the HTML either — all styling lives in `style.css`.
* **Class/ID Selectors Only:** All design properties, layout rules, and states must be targeted via class or ID selectors.
* **Minimal HTML Modifications:** HTML must remain clean, semantic, and styling-agnostic — changing the site's entire look must require editing only `style.css`.

**1.2 CSS Variables & Theme Tokens**
Store all visual tokens in `:root` (and theme selectors). Required tokens and their values for this theme:
* **Colors:** `--primary: #FF10F0` (neon pink); `--secondary: #0066CC` (dull blue); `--bg-primary: #FFF6E5` (cream poster paper — never pure white); `--bg-secondary: #FEFEFE` (near-white paper); `--text-primary: #000000`; `--text-secondary: #333333`; `--text-success: #007A00`; `--text-error: #B00000`; `--border-default: #000000`; `--border-error: #FF0000`; `--border-success: #008A00`.
* **Fluorescent accents:** `--accent-yellow: #FFFF00`; `--accent-green: #00FF00`; `--accent-orange: #FF6600`; `--accent-red: #FF0000`; `--accent-purple: #FF00FF`; `--accent-pink: #FF10F0`.
* **Shape & depth:** `--radius-sm: 2px`; `--radius-md: 4px`; `--radius-lg: 8px`; `--shadow-sm: 3px 3px 0 #000`; `--shadow-md: 5px 5px 0 #000` (hard offset shadows only — never blurred); `--shadow-text: 2px 2px 0 rgba(0,0,0,0.2)`.
* **Spacing & motion:** `--spacing-gap: 1.5rem`; `--transition-fast: 120ms`; `--transition-normal: 250ms`; `--ease-standard: cubic-bezier(0.2, 0, 0.3, 1)`.
* **Layering:** `--z-dropdown: 1000`; `--z-modal: 1050`; `--z-toast: 1100`.
* **Type:** `--font-display: 'Anton', 'Oswald', sans-serif`; `--font-marker: 'Permanent Marker', cursive`; `--font-base: 'Archivo', sans-serif`.
* **Contrast Pairing:** Every light background token must pair with a dark text token and every dark background token with a light text token — enforced in every theme. Fluorescent accents count as light backgrounds → always black text on them.

**1.3 Mandatory Dark Mode ("Night Market" Variant)**
* Define dark tokens under **both** `@media (prefers-color-scheme: dark)` and a `.dark` class on `<html>` (the class overrides the media query).
* Dark tokens: `--bg-primary: #121212`; `--bg-secondary: #1E1E1E`; `--text-primary: #FEFEFE`; `--text-secondary: #C9C9C9`; `--border-default: #FEFEFE`; `--shadow-sm`/`--shadow-md` switch to light (`#FEFEFE`) so hard-shadow depth stays visible; `--text-success: #5CFF5C`; `--text-error: #FF6B6B`; success/error borders brighten accordingly. Fluorescent accents remain unchanged (they glow on dark), and fluorescent fills keep black text.
* **Theme Switching:** Provide a visible header toggle (Material Symbol `light_mode`/`dark_mode`) with correct `aria-pressed` and dynamic `aria-label`. Persist the choice in `localStorage`; fall back to `prefers-color-scheme` on first visit. Apply the stored preference at the top of `script.js` to minimize flash. Switching must require zero HTML restructuring.
* **Exception clause:** The source style spec requested light-mode-only; dark mode remains a mandatory architectural requirement — implement the Night Market variant exactly as specified above.

**1.4 Flexbox Layout & Mobile-First Alignment**
* Build all layout structures with Flexbox. Every flex container must default to `align-items: center` unless there is an explicitly commented exception (e.g., `stretch` on card content columns).
* Mobile-first: rows convert to columns below ~768px; no horizontal scrolling at any viewport; fluid type via `clamp()`; minimum 44x44px touch targets on all interactive elements.

**1.5 Framework Default & Tailwind CSS Integration**
* Use Tailwind CSS via CDN for structural/layout utilities (flex, gap, padding, responsive prefixes) **or** clean custom CSS organized with `@layer`/`@apply` — pick one approach and stay consistent.
* All visual styling lives in `style.css` as reusable component classes (`.btn`, `.card`, `.input-group`, `.accordion`, `.plan`, `.ribbon`, `.starburst`) bound to the CSS variables. Never hardcode hex values outside the token definitions.

**1.6 Typography & Icons (Google Fonts Mandatory)**
* Load via Google Fonts `<link>` (with `preconnect`): **Anton** (display), **Permanent Marker** (handwritten annotations), **Archivo** 400/600/700 (body). Bind them to `--font-display`, `--font-marker`, `--font-base`.
* **Exception clause:** The source spec lists the system font 'Impact'; it is forbidden — substitute Google Font **Anton**, which delivers the same condensed garrafais look.
* Display type: `text-transform: uppercase`, visually heavy weight, `letter-spacing: -0.5px` on large headlines, tight line-height (~0.95–1.1). Apply `--shadow-text` to display headlines for printed-ink depth.
* **Icons:** Google Material Symbols (Outlined) via the official stylesheet, using `font-variation-settings` for filled variants (e.g., stars). Inline SVGs and local icon files are forbidden.

## 2. THEME DESIGN SYSTEM — CARTAZISTA DE SUPERMERCADO

**2.1 Signature Visual Techniques (CSS-only, no images):**
* **Poster borders:** 4–5px solid `var(--border-default)` on cards, banners, buttons; use asymmetric `border-radius` values to simulate wobbly hand-drawn frames.
* **Hard shadows:** `var(--shadow-md)` offset shadows everywhere; never diffuse shadows.
* **Paper texture:** subtle CSS-only grain on `--bg-primary` via layered, low-opacity repeating gradients — subtle enough to preserve text contrast.
* **Starburst badges:** multi-point star shapes via `clip-path` polygons; fluorescent fill + black uppercase Anton text; rotated between -6deg and 6deg. Use for "SALE!", "BEST SELLER", "48H".
* **Price ribbons/tags:** rectangular price-tag shapes with a punched-hole circle (radial-gradient) or ribbon-tail `clip-path`; rotated ~-2deg; Anton numerals.
* **Crepe tape strips:** short, semi-transparent tape rectangles (pseudo-elements) anchoring cards/notes, rotated a few degrees.
* **Marker highlights:** a fluorescent linear-gradient swipe behind one key headline word (highlighter-pass effect); wavy/dashed marker underlines and dividers.
* **Hand-placed feel:** rotate decorative elements between -2deg and 2deg; never rotate body paragraphs or form controls; straighten rotations on hover when elements lift.
* **Dense composition:** hero and pricing sections feel information-dense (badges, annotations, tags, overlapping fluorescent shapes); body sections stay readable.

**2.2 Color Usage & Contrast Rules (mandatory, both themes):**
* Black text on ALL fluorescent fills and on cream/near-white surfaces.
* Fluorescent text ONLY on black/near-black surfaces (footer, dark buttons, featured plan).
* Never: fluorescent text on cream/white; white text on orange/yellow/green; neon green body text on light backgrounds.
* Body text always uses `--text-primary`/`--text-secondary`. Fluorescents are reserved for fills, display headlines on black, badges, and accents.

## 3. PAGE SECTIONS BUILD SPECIFICATION

Build in this order inside semantic landmarks (`header`, `nav`, `main`, `footer`), with a visually hidden skip-to-content link as the first focusable element. Anchor links scroll smoothly (disabled under `prefers-reduced-motion`).

**3.1 Header (sticky):** Cream paper background, 4px black bottom border. Flex row: brand wordmark (Anton, uppercase — invent a short punchy name, e.g., "MEGASIGN CO."), nav links (Features, How It Works, Pricing, FAQ) with marker-style focus states, theme toggle (per 1.3), CTA button "GET A QUOTE". Mobile: hamburger button (`aria-expanded`, `aria-controls`) opening a flex-column panel at `--z-dropdown`; closes on Esc and link selection.

**3.2 Hero:** Dense cartaz composition on paper texture: a fluorescent yellow top strip with black uppercase eyebrow copy (e.g., "HAND-PAINTED POSTERS FOR STORES THAT SELL OUT") plus a rotated "SALE!" starburst; a single `h1` in Anton (`clamp(2.75rem, 8vw, 5.5rem)`, uppercase), e.g., "YOUR MEGA OFFERS DESERVE A MEGA POSTER", with the marker-highlight swipe on one key word; subcopy in Archivo explaining the studio and 48h turnaround; two CTAs (`.btn--primary` "ORDER MY POSTER", `.btn--outline` "SEE PRICING"); a rotated "FROM $49" price-tag ribbon with punched-hole detail; one Permanent Marker annotation (e.g., "painted by real humans!") with a marker underline; layered decorative CSS shapes (fluorescent circles, strips, tape). No photos, no external images.

**3.3 Features — 3 cards:** Anton section heading with marker underline + short lead. Three `.card` elements in a flex row (column on mobile), each a mini cartaz: 4px black border, hard shadow, a distinct fluorescent fill per card (yellow, pink, green) with black text, a Material Symbol icon in a black circular chip, an Anton title, 2–3 sentences of body copy, and a small corner ribbon ("HOT!", "NEW!", "TOP!"). Alternate slight rotations (-1deg / 0 / 1deg). Suggested copy: "LETTERS YOU CAN'T IGNORE" (garrafais visibility), "READY IN 48 HOURS" (brief-to-wall turnaround), "PRICES THAT POP" (fluorescent color systems tested on real retail floors).

**3.4 How It Works — 3 steps:** Flex row (column on mobile) of three steps, each with a starburst or price-tag number chip ("1", "2", "3" in Anton), an Anton step title, and short copy; connect steps with a dashed marker line (hidden on mobile). Copy: "SEND YOUR OFFER" (product, price, size) → "WE PAINT IT" (sketch, brush, fluorescent inks) → "HANG & SELL" (delivered rolled or framed).

**3.5 Testimonials — 3 quotes:** Cards styled as taped paper notes: `--bg-secondary` paper, crepe-tape strip on the top edge, slight alternating rotations. Each contains a 5-star rating using filled Material Symbol stars **plus** the text "5/5" (never icon/color alone), a quote in Permanent Marker or Archivo italic, and an invented customer name + role in small Anton caps (e.g., "ANA — CORNER GROCERY OWNER").

**3.6 Pricing — 3 tiers:** Styled as supermarket price cartazes. Each `.plan`: fluorescent header band (yellow / pink / green) with the plan name in Anton uppercase, a huge Anton price with a per-unit note, a feature list with Material Symbol check icons, and a CTA button. The featured middle plan uses a black background with fluorescent text, larger scale, an elevated shadow, and a "BEST SELLER" starburst badge — distinguishable by more than color alone (badge text + size). Suggested tiers: "COUNTER CARD — $49" (single A3 poster), "WINDOW MEGA — $99" (A1 window poster + price tags) [featured], "FULL STORE — $249" (5-piece campaign set + hanging guide).

**3.7 FAQ — accessible accordion:** 5–6 real Q&As (sizes, materials, 48h turnaround, revisions, delivery, bulk discounts) in plausible English copy. Implement with the button (`aria-expanded`, `aria-controls`) + region pattern or styled `<details>`/`<summary>`; a Material Symbol plus/minus icon rotates on open; smooth CSS height transition; fully keyboard operable; marker-style borders between items.

**3.8 Final CTA:** Full-width fluorescent yellow banner with paper texture and black text: giant Anton headline (e.g., "DON'T LET YOUR OFFER GO UNNOTICED!"), short subcopy, a rotated "ORDER TODAY!" starburst, and an email-capture `.input-group` ("Get the full price list") with a `.btn--dark` submit. The form must exercise every state in 4.3 and announce success via an inline message plus an `aria-live` toast at `--z-toast`.

**3.9 Footer:** Black background in **both** themes (in dark mode, adjust borders so it stays distinct from `--bg-primary`). Brand wordmark, three columns of secondary links (Product: Features, Pricing, FAQ; Company: About, Contact, Careers; Support: Help, Shipping, Returns), a social icon row (Material Symbols with `aria-label`), copyright line, and small print. Links get visible focus states, 44px targets, and hover underlines.

## 4. COMPONENT DESIGN SPECIFICATIONS

**4.1 Buttons (`.btn` + variants `.btn--primary`, `.btn--dark`, `.btn--outline`, `.btn--danger`):**
* **Default:** `display: flex; align-items: center; justify-content: center; gap: 0.5rem;` minimum 44x44px; uppercase Anton label; 3–4px black border; `--radius-sm`; hard shadow. Variants: `--primary` = fluorescent yellow fill + black text; `--dark` = black fill + fluorescent yellow text; `--outline` = transparent fill + black border (inverted in dark mode); `--danger` = `--accent-red` fill + black text + black border, visually distinct in both themes.
* **Hover:** `translate(-2px, -2px)` with the shadow growing (e.g., to 7px 7px 0) — the "poster lift"; `cursor: pointer`.
* **Focus:** a 3px dashed outline (offset 3px) in a high-contrast token — the marker focus ring; never remove it.
* **Active/Pressed:** `translate(2px, 2px)`, shadow collapses, `transform: scale(0.97)` — the "stamp press".
* **Loading (`.is-loading`):** interactions disabled, `aria-busy` set, double submits prevented; a CSS spinner or animated Material Symbol renders without changing button dimensions.
* **Disabled:** `opacity: 0.5`, grayscale, `cursor: not-allowed`, no hover transforms.
* **Success/Error (`.is-success` / `.is-error`):** temporary feedback styles driven by `--text-success`/`--text-error`, always paired with an icon and/or text — never color alone.

**4.2 Cards (`.card`):**
* **Default:** flex column, `--bg-secondary` (or fluorescent fill variant classes), 4px black border, hard shadow, `--radius-sm`, comfortable padding.
* **Hover (interactive cards):** straighten rotation, `translateY(-2px)`, shadow grows.
* **Focus-within:** border shifts to `--primary` and/or thickens so keyboard users see the highlight when a child link/button is focused.
* **Loading (Skeleton):** define a shimmer variant (animated gradient) for any async content.
* **Empty State:** define a fallback pattern — large Material Symbol + short guidance text — even if unused on this page.

**4.3 Forms & Inputs (`.input-group`):**
* **Structure:** flex column wrapping a `<label>`, the `<input>`, and a dedicated error/feedback container bound to `aria-live`.
* **States (all via classes):** empty; focused (thick marker ring using `--secondary` or dashed outline); filled; valid (`--border-success` + check icon); invalid (`--border-error` + error icon + red message text, announced via `aria-live`); disabled; read-only.
* The Final CTA email capture must validate in JS with visible success (inline confirmation + toast) and error (icon + message) feedback.

**4.4 Accordion & Modal/Overlay:**
* **FAQ accordion:** open/close animated via CSS transitions; honors `prefers-reduced-motion`; `aria-expanded` toggled; no mouse-only interactions.
* **Modal (if any overlay is implemented):** centered via flex (`align-items: center`), backdrop overlay, Material Symbol close button, keyboard focus trapping, close via Esc and overlay click, and animated opening/open/loading/success/closing states at `--z-modal`.

## 5. CORE UX & MICRO-INTERACTION RULES

* **Responsive by default:** fluid `clamp()` sizing, breakpoints without horizontal overflow, rows → columns on small viewports.
* **Smooth animations:** `transition: var(--transition-normal)` on all state changes; honor `prefers-reduced-motion` (disable shimmer, rotations, lifts, smooth scroll, and long transitions).
* **Accessibility (a11y):** AA contrast in both modes per the pairing rules in 2.2; semantic HTML5 landmarks and a correct heading hierarchy (one `h1`); correct ARIA on the theme toggle, mobile menu, accordion, and form feedback; logical DOM/focus order; full keyboard operability; `aria-live` regions for dynamic feedback (form errors, toasts, loading states).
* **Mandatory visual feedback:** every click, hover, focus, and submission produces a visible state change.
* **Never color-alone state communication:** pair color with icons and text everywhere.
* **Destructive actions:** any `.btn--danger` must be visually distinct in both light and dark themes.

## 6. DELIVERABLE & OUTPUT FORMAT

* **Files:** separate `index.html`, `style.css`, and `script.js`. Exactly one `<script src="script.js" defer>` reference; no inline script blocks, no inline styles, no `<style>` blocks in HTML.
* **Head assets:** `preconnect` + Google Fonts stylesheet (Anton, Permanent Marker, Archivo) + Material Symbols stylesheet.
* **Naming convention:** BEM exclusively (`.hero__title`, `.card--yellow`, `.btn--primary`, `.plan--featured`, `.faq__item`, `.footer__link`). If Tailwind is chosen, its utilities may only handle structure (flex/gap/spacing/responsive) — never colors or theme visuals. Never mix conventions.
* **Copy:** all user-facing copy in English, in a loud retail-promotional voice (short punchy all-caps display lines, friendly body text). Write real copy for every section per the direction in Section 3 — lorem ipsum is forbidden. **Exception clause:** a single decorative Portuguese word (e.g., "OFERTA!") may appear as a thematic sticker/badge accent, since it functions as part of the visual identity; all functional copy, labels, buttons, and body text remain English.
* **No unrequested placeholders:** no photos, no external images, no dummy widgets — every visual is CSS-composed per Section 2.
* Deliver the complete, working page in one response: `index.html`, `style.css`, `script.js`.