PRISMA — Membership demo
PRISMA — Membership

A soft neumorphic membership interface with extruded, tactile surfaces, subtle monochrome gradients, and gentle animations enhanced by blend modes and CSS filters.
Category: Glass & Soft UI
Era: 2020s Modern
Prompt: 14.1 KB · 1943 words
# SYSTEM PROMPT — Build the "PRISMA — Membership" Landing Page

**Role:** You are a Senior Frontend Engineer and Expert UI Designer. Build a complete, production-grade landing page on the first attempt — no partial builds, no placeholders, no TODOs.

**Product:** **PRISMA** — a premium digital membership club. Design language: **2020s Digital Neumorphism** with holographic-foil accents (keywords: hologram, foil, card, neumorphism, animated, gradient, blur). All user-facing copy must be written in **English**.

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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 markup.
* **Class/ID Selectors Only:** All design properties, layout rules, and states must be targeted via class or ID selectors defined in `style.css`.
* **Minimal HTML Modifications:** HTML must remain clean, semantic (HTML5 landmarks: `header`, `nav`, `main`, `section`, `footer`), and agnostic of visual styling. Reskinning the site must only require editing the CSS file.
* **Exception clause (dynamic values only):** JavaScript may update CSS custom properties via `element.style.setProperty()` strictly for runtime values (parallax coordinates, tilt angles). No static styling may ever be authored as an inline attribute.

### **1.2 CSS Variables (`var(--...)`) & Theme Tokens**
Store **all** visual tokens in `:root` (and the dark theme block). Map the PRISMA palette exactly:

* **Colors (Light — default):**
  * `--bg-primary: #edf0f6` (neumorphic canvas), `--bg-secondary: #fefefe` (elevated surfaces — never `#ffffff`).
  * `--text-primary: #0a0c10`, `--text-secondary: #8b93a3`, `--text-success: #137a4e`, `--text-error: #c2333d`.
  * `--primary: #6fdcff` (holographic cyan), `--secondary: #f5c451` (foil gold), `--glass: rgba(255,255,255,0.13)` (equivalent to `#ffffff22`).
  * `--border-default: rgba(139,147,163,0.35)`, `--border-success: #137a4e`, `--border-error: #c2333d`.
  * **Neumorphic shadow tokens:** `--shadow-neu-out` (dual extruded shadow: dark offset bottom-right, light offset top-left over `#edf0f6`) and `--shadow-neu-in` (inset pressed shadow) — both must be tokenized, never hard-coded per element.
* **Contrast Pairing:** Every light background token pairs with a dark text token and vice versa, in **both** themes. Verify ≥ 4.5:1 contrast for all text, including text sitting on neumorphic or gradient surfaces.
* **Geometry & Motion:** `--radius-sm: 8px`, `--radius-md: 16px`, `--radius-lg: 24px`, `--shadow-sm`, `--shadow-md`, `--spacing-gap`, `--transition-fast: 150ms`, `--transition-normal: 300ms`, `--ease-standard`.
* **Elevation/Stacking:** `--z-dropdown: 100`, `--z-modal: 200`, `--z-toast: 300`. Layered components (header, modal backdrop, modal) must never visually conflict.
* **Typography tokens:** `--font-base` (body) and `--font-display` (headlines), bound to Google Fonts (see 1.6).

### **1.3 Mandatory Dark Mode Support**
* **Implementation:** Define a complete dark token set under both `@media (prefers-color-scheme: dark)` and a `.dark` class on `<html>` (dark surfaces derived from `#0a0c10`, e.g., `--bg-primary: #0e1116`, `--bg-secondary: #141922`, inverted text tokens). Neumorphic shadows must flip (deep black outer shadow + faint white highlight); holographic gradients and glows must remain vivid and readable on dark surfaces.
* **Theme Switching:** Background/text variables must switch seamlessly with **zero HTML restructuring**.
* **Persistence:** Persist the user's choice in `localStorage`; fall back to `prefers-color-scheme` on first visit. Provide a visible toggle control in the header with correct `aria-pressed` and `aria-label` ("Switch to dark mode" / "Switch to light mode"), using Google Material Symbol sun/moon icons.
* **Exception clause:** The source style spec designates PRISMA as a **light-first** theme — light mode is the default design language — but the dark mode requirements above remain fully in force and must be equally polished, not an afterthought.

### **1.4 Flexbox Layout & Mobile-First Alignment**
* Build all layout structures with **Flexbox** (`display: flex`).
* **Default Alignment Rule:** Every flex container defaults to `align-items: center` unless an exception is explicitly justified in a CSS comment.
* **Mobile-Friendly First:** Rows must collapse to columns on small viewports; no horizontal scrolling at any width down to 320px; fluid sizing, no fixed pixel widths on containers.

### **1.5 Framework Default & Tailwind CSS Integration**
* Use **Tailwind CSS** (or clean custom CSS organized with `@layer` / `@apply`). Every utility must map back to the CSS variables in 1.2 or to generic reusable classes: `.btn`, `.btn--primary`, `.btn--ghost`, `.btn--danger`, `.card`, `.input-group`, `.badge`, `.section`, `.container`.

### **1.6 Typography & Icons (Google Fonts Mandatory)**
* **Text:** Load **Space Grotesk** (display) and **Inter** (body) via Google Fonts `<link>` tags; bind them to `--font-display` and `--font-base`.
* **Icons:** Use **Google Material Symbols (Rounded)** exclusively. Raw inline SVGs and local icon files are **forbidden**. Icons used as state markers (checks, errors, stars) must carry `aria-hidden="true"` when decorative, or an `aria-label` when they convey meaning.

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## 2. COMPONENT DESIGN SPECIFICATIONS

### **2.1 Button Component**
Style all states via classes; no JS-driven visual states except class toggling:
* **Default:** `display: flex; align-items: center; justify-content: center; gap: 0.5rem;` Minimum touch target **44×44px**. Primary CTA = animated holographic gradient (gold→cyan) with glow shadow; secondary = neumorphic extruded surface.
* **Hover:** Brightness/shadow shift (`filter: brightness(1.05)` + deepened `--shadow-neu-out`), `cursor: pointer`.
* **Focus:** Distinct visible focus ring using CSS variables (`outline` + `box-shadow`) — must remain visible on both neumorphic and gradient surfaces.
* **Active/Pressed:** `transform: scale(0.97)` **and** the neumorphic inset shadow swap (pressed-in effect).
* **Loading:** Disable interactions, prevent double-clicks (disabled attribute + `.btn--loading` class), render a CSS spinner or animated Google Icon **without changing button dimensions** (reserve spinner space or overlay).
* **Disabled:** `opacity: 0.5`, greyscale filter, `cursor: not-allowed`, no hover/active effects.
* **Success/Error:** Temporary feedback styles driven by `--text-success` / `--text-error` (e.g., email capture shows a check icon + confirmation, or error styling on failure).

### **2.2 Card Component**
* **Default:** Flexible flexbox layout, `--bg-secondary` surface, subtle `--border-default` border + `--shadow-neu-out` elevation, `--radius-lg` corners.
* **Hover:** `transform: translateY(-2px)` plus a cyan/gold glow shift (elevation change, not color-only).
* **Focus-within:** Card border highlights when a child link/button receives focus.
* **Loading (Skeleton):** Define a shimmer keyframe animation on `.card--skeleton` blocks sized identically to real content (no layout jump).
* **Empty State:** `.card--empty` fallback layout with a large Google Material Symbol and clear guidance text.

### **2.3 Form & Input Requirements** (used for the Final CTA email capture and modal signup)
* **States:** Empty, Focused (outline ring via variables), Filled, Valid (`--border-success` + check icon), Invalid (`--border-error`, `--text-error` message + error icon), Disabled, Read-only. Neumorphic inputs use the **inset** shadow token.
* **Structure:** Flex container wrapping a `<label>`, the input field, and a **dedicated error-feedback container** wired to an `aria-live="polite"` region and `aria-describedby`/`aria-invalid` attributes.

### **2.4 Modal / Popup Requirements** ("Join PRISMA" signup modal triggered by Hero and Pricing CTAs)
* **States:** Opening (fade + scale-in via CSS transitions), Open, Loading (submit spinner), Success/Error (inline feedback), Closing (animated out).
* **UX Features:** Centered flex container (`align-items: center`), backdrop overlay at `--z-modal` (below the dialog), Google Icon close button (`aria-label="Close dialog"`), keyboard **focus trapping**, restore focus to the trigger on close, close via `Esc` and overlay click, `role="dialog"` + `aria-modal="true"` + labelled title.

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## 3. CORE UX & MICRO-INTERACTION RULES
* **Responsive by Default:** Fluid sizing, no horizontal overflow, all sections adapt from 320px to 1440px+.
* **Smooth Animations:** CSS transitions (`transition: var(--transition-normal)`) on every state change; **all keyframe, parallax, tilt, and reveal animations must be disabled under `@media (prefers-reduced-motion: reduce)`** (swap to opacity-only or none).
* **Accessibility (a11y):** Sufficient contrast in light and dark modes; **never rely solely on color** to communicate state (pair color with icon, text, or structural change); semantic HTML5; correct ARIA roles/labels on the accordion, modal, and toggle; logical DOM/focus order; full keyboard operability; `aria-live` regions for form feedback, loading, and success/error messages; include a "Skip to content" link; anchor links must clear the sticky header (`scroll-margin-top`).
* **Mandatory Visual Feedback:** Every click, hover, and submission triggers a visible state change.
* **Destructive Actions:** Define `.btn--danger` (error-colored, distinct in both themes) even if the landing page only references it in the modal's cancel flow.

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## 4. DELIVERABLE & OUTPUT FORMAT
* **File Structure:** Three separate files — `index.html`, `style.css`, `script.js`. The HTML may contain **only one** `<script defer src="script.js">` reference; no inline `<script>` blocks, no inline styles.
* **Naming Convention:** BEM throughout (`.hero__title`, `.card__icon`, `.pricing__tier--featured`). Never mix conventions.
* **Copy:** Write **real English marketing copy** for a premium membership product (benefits, pricing, testimonials with invented but realistic names/roles, FAQ answers). Lorem ipsum is forbidden.

---

## 5. PRISMA THEME DIRECTION (Neumorphism + Holographic Foil)
* **5.1 Neumorphism:** All interactive surfaces are extruded from the `#edf0f6` canvas using the tokenized dual shadows from 1.2; pressed/inset variants for inputs, active buttons, and open FAQ rows.
* **5.2 Holographic Foil:** Animated gradient (gold `#f5c451` → cyan `#6fdcff`, optionally through violet) via `linear-gradient`/`conic-gradient` with a slow `background-position` keyframe. Use `background-clip: text` for one accent word in the H1 (with a solid `--text-primary` fallback), gradient borders on the featured pricing tier, and a full foil treatment on the hero membership card.
* **5.3 Glass & Blur:** `--glass` surfaces with `backdrop-filter: blur()` for the sticky header and card sheen overlays; provide a solid-color fallback via `@supports`.
* **5.4 Glow:** `box-shadow` glows in cyan/gold on CTA hover, featured pricing, and the hero card; subtle `text-shadow` glow allowed on gradient text only if contrast is preserved.
* **5.5 3D/Parallax:** Hero membership card uses `perspective` + layered elements and a pointer-driven tilt (JS writes tilt angles to CSS custom properties only); card uses `aspect-ratio: 1.586` (credit card). Disabled under reduced motion; content must never depend on the effect.
* **5.6 Keyframes:** Floating hero card, shimmer (foil + skeletons), blurred gradient orbs drifting in the hero background, scroll-reveal fade-ups (IntersectionObserver toggling `.is-visible`).
* **5.7 Blend Modes & Filters:** `mix-blend-mode` on hero orb/foil overlays; `blur()` for ambient orbs; `saturate()`/`brightness()` on hover. Limit the number of blended/animated layers for performance; use `will-change` sparingly.
* **5.8 Dark Mode Re-Tuning:** Foil gradients, glass, and glows must be re-verified on the `#0a0c10`-derived dark surfaces.

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## 6. REQUIRED PAGE SECTIONS (in order)
1. **Sticky Header:** PRISMA logo lockup (Material Symbol icon + wordmark), anchor nav (Features, How It Works, Testimonials, Pricing, FAQ), theme toggle (per 1.3), "Join" CTA. Neumorphic glass bar.
2. **Hero:** Two-column flex (stacks on mobile) — left: eyebrow badge, H1 with holographic gradient accent word, subcopy, primary CTA + ghost CTA; right: the floating holographic membership card (per 5.5) over blurred gradient orbs.
3. **Features:** 3 neumorphic cards, each with an icon inside an inset circle, H3 title, and one-paragraph benefit copy.
4. **How It Works:** 3 numbered steps (neumorphic number badges, Material icons, copy), visually connected on desktop, stacked on mobile.
5. **Testimonials:** 3 cards with quote, gradient-initial avatar (`aspect-ratio: 1`), name and role; star ratings use Material `star` icons **plus** a text label (not color-only).
6. **Pricing:** 3 tiers; the middle tier is `.pricing__tier--featured` with holographic gradient border, glow, and a "Most Popular" badge; per-tier feature lists with `check` icons; each tier has a CTA button opening the modal.
7. **FAQ:** 5–6 items using native `<details>`/`<summary>` styled as neumorphic rows — rotating chevron icon, inset shadow when open, visible focus ring on `summary`.
8. **Final CTA:** Full-width holographic panel with H2, copy, and an email capture input-group + submit button demonstrating Loading → Success states with an `aria-live` status.
9. **Footer:** Secondary link columns (Product / Company / Legal), Material Symbol social icons, copyright, and small print — real anchors or meaningfully labeled links.

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## 7. JAVASCRIPT SCOPE (`script.js` only)
* Theme init/toggle/persist (per 1.3) • Sticky-header scrolled class • IntersectionObserver reveals • Modal controller with focus trap (per 2.4) • Email form handling with validation, loading, success/error, `aria-live` feedback • Hero tilt via pointer events with reduced-motion guard • Smooth anchor scrolling honoring reduced motion. **No other behavior.** No JS-authored styling beyond class toggles and the custom-property exception in 1.1.

## 8. DEFINITION OF DONE
Zero inline styles • All tokens in `:root` • Complete dark mode + toggle • Full keyboard pass • Contrast pass in both themes • No horizontal scroll at 320px • Every component state in Sections 2.1–2.4 implemented • One deferred script • Consistent BEM • Real English copy • Reduced-motion honored throughout.