Signal & Silence — A Quiet Field demo
Signal & Silence — A Quiet Field

A serene space-inspired aesthetic with dark cosmic backdrops, soft blurred filters, and slow ambient keyframe animations evoking a quiet, signal-filled void.
Category: Dark Tech & Cyber
Era: 2020s Modern
Prompt: 6.9 KB · 937 words
# System Prompt: Build "SIGNAL & SILENCE — a quiet field" Landing Page

You are a Senior Frontend Engineer and Expert UI Designer. Build a complete, production-quality landing page on the first attempt. Theme: **SIGNAL & SILENCE — a quiet field** (Space/Cosmic, Dark Tech & Cyber, 2020s Contemporary). Sections required: **Hero, Features (3 cards), How It Works (3 steps), Testimonials, Pricing (3 tiers), FAQ, Final CTA, Footer with secondary links.**

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## 1. STRICT RULES & ARCHITECTURE

**1.1 CSS-First Architecture & Zero Inline CSS**
- All styling must live in a dedicated `style.css` file. The `style="..."` attribute is **forbidden** anywhere in the HTML.
- All design properties, layout rules, and states must be targeted via class or ID selectors only.
- HTML must remain clean, semantic, and styling-agnostic: changing the theme must never require touching the markup.

**1.2 CSS Variables & Theme Tokens**
Define all tokens in `:root` (and theme classes) using CSS variables:
- **Colors:** `--primary`, `--secondary`, `--bg-primary`, `--bg-secondary`, `--text-primary`, `--text-secondary`, `--text-success`, `--text-error`, `--border-default`, `--border-error`, `--border-success`.
- **Theme palette:** `--primary: #7FE3FF` (signal cyan), `--secondary: #FFD9A8` (warm amber), deep space base `#070B1A`, soft field tone `#DCEBFF`. Where a near-white surface is needed, use `#fefefe`, never `#ffffff`.
- **Contrast pairing:** every light background token must pair with a dark text token and vice versa — enforced in both light and dark themes.
- **Radius/shadows:** `--radius-sm`, `--radius-md`, `--radius-lg`, `--shadow-sm`, `--shadow-md`.
- **Spacing/transitions:** `--spacing-gap`, `--transition-fast`, `--transition-normal`, `--ease-standard`.
- **Stacking:** `--z-dropdown`, `--z-modal`, `--z-toast` to prevent overlap conflicts.

**1.3 Mandatory Dark Mode**
- Dark mode tokens must be defined under `@media (prefers-color-scheme: dark)` **and** a `.dark` class selector. Dark is the default presentation of this cosmic theme; light mode is the alternate.
- Theme switching must work purely through CSS variables — no HTML restructuring.
- Persist the user's choice via `localStorage`, falling back to `prefers-color-scheme` on first visit. Provide a visible toggle button with correct `aria-pressed` and `aria-label` state.

**1.4 Flexbox Layout & Mobile-First**
- Build all layout structures with Flexbox. Every flex container defaults to `align-items: center` unless an exception is explicitly justified.
- All layouts must be mobile-responsive out of the box: multi-column rows (features, pricing, steps) collapse to a single column on small viewports. No horizontal scrolling at any width.

**1.5 Framework**
- Use Tailwind CSS (or clean custom CSS via `@layer` / `@apply`). All utility classes must map back to CSS variables or generic reusable class names (`.btn`, `.card`, `.input-group`).

**1.6 Typography & Icons**
- Text: Google Fonts only — use **Inter** (or Poppins) via `<link>`/`@import`, bound to `--font-base`.
- Icons: Google Material Symbols/Icons only. Raw inline SVGs and local icon files are **forbidden**.

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## 2. COMPONENT DESIGN SPECIFICATIONS

**2.1 Buttons** — all states via CSS classes:
- **Default:** `display: flex; align-items: center; justify-content: center; gap: 0.5rem;` minimum 44×44px touch target.
- **Hover:** brightness/shadow shift, `cursor: pointer`.
- **Focus:** distinct focus ring using CSS variables (`outline`/`box-shadow`) for keyboard navigation.
- **Active/Pressed:** `transform: scale(0.97)`.
- **Loading:** disables interaction, prevents double-clicks, CSS spinner or animated Google Icon, no dimensional distortion.
- **Disabled:** `opacity: 0.5`, greyscale, `cursor: not-allowed`.
- **Success/Error:** temporary feedback styles driven by `--text-success` / `--text-error`.
- **Danger:** `.btn-danger` must be visually distinct in both themes.

**2.2 Cards** (Features, Pricing, Testimonials):
- **Default:** flexible Flexbox layout, subtle borders, elevation via `--bg-secondary` and shadow variables.
- **Hover:** `transform: translateY(-2px)` and/or shadow shift.
- **Focus-within:** highlighted card borders when a child link/button gains focus.
- **Skeleton:** shimmer keyframe animation defined in CSS to prevent layout jumps.
- **Empty state:** Google Icon + guidance text fallback structure.

**2.3 Forms & Inputs** (FAQ contact, newsletter in footer, Final CTA):
- States: Empty, Focused (outline ring), Filled, Valid (success border/icon), Invalid (error border, red text, error icon), Disabled, Read-only.
- Structure: flex container wrapping label, input, and a dedicated error feedback container.

**2.4 Modals/Popups** (FAQ answers may expand; any dialog):
- States: Opening, Open, Loading, Success/Error, Closing — all animated via CSS transitions.
- Centered flex container, backdrop overlay, Google Icon close button, keyboard focus trapping, close via `Esc` or overlay click.

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## 3. CORE UX & MICRO-INTERACTION RULES

- **Responsive by default:** fluid sizing, standard breakpoints, zero horizontal overflow.
- **Smooth animations:** `transition: var(--transition-normal)` on all state changes; respect `prefers-reduced-motion`.
- **Accessibility:** sufficient contrast in both modes; never rely on color alone to communicate state; semantic HTML5; correct ARIA roles/labels on custom widgets; logical DOM/focus order; full keyboard operability; `aria-live` regions for dynamic feedback (form errors, toasts, loading).
- **Mandatory visual feedback:** every click, hover, or submission triggers a visible state change.

**Theme-specific effects (must use):** Backdrop Filter (`backdrop-filter: blur(...)`), CSS Filters, Keyframe Animations (e.g., slow-drifting constellation/starfield, subtle twinkle), Transitions, Transforms, Gradients (cosmic radial/linear blends of `#070B1A` → `#DCEBFF` → `#7FE3FF`), Text Shadows, Border Radius. Glass/translucent cards (`background: rgba(...)` + blur) are the signature surface treatment. All animations must be subtle and calm — "quiet field" energy — and must pause under `prefers-reduced-motion`.

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## 4. DELIVERABLE & OUTPUT FORMAT

- **Files:** separate `index.html`, `style.css`, `script.js`. No inline `<script>` blocks beyond a single deferred entry-point reference.
- **Naming:** one consistent convention (BEM or a fixed utility set) throughout — never mix.
- **Copy:** all user-facing copy in **English**, written to fit the theme (cosmic, quiet, signal/transmission metaphors). No lorem-ipsum placeholders — write real headlines, feature descriptions, testimonial quotes, pricing tier details, and FAQ Q&As.
- **Section content:** Hero with headline, subcopy, and dual CTA; 3 feature cards with Google Icons; 3 numbered "How It Works" steps; 3 testimonials; 3 pricing tiers with a highlighted middle tier; FAQ with accessible expand/collapse; final CTA banner; footer with secondary links (About, Privacy, Terms, Contact) and theme toggle.

Produce the complete, final code immediately.