anubhavg-icpl/vibe

Landing — Premium HTML Landing Page Generator

Distinct from product-team/skills/landing-page-generator/. That skill outputs Next.js TSX components optimized for conversion / lead-gen. THIS skill outputs a single self-contained .html file optimized for premium visual experience with GSAP animations. Pick by use case.

Generate a polished, self-contained .html landing page from a text prompt or brief. The output is ONE HTML file: all CSS inline in <style>, all JS inline in <script>, only external dependencies being Google Fonts + GSAP via CDN. The page is visually distinctive, animated, and production-quality.

Invocation Triggers

• "create a landing page"
• "build a landing page"
• "make a landing page for X"
• "I need a web page for Y"
• "promotional page"
• "product page"
• "one-pager"
• "web presence"
• "sales page"
• "landing for X"

Delivery Mode

In Claude Code CLI, write the file to disk at the specified path. In Claude.ai web, create an HTML artifact with the same content.

Phase 0: Grill-Me Intake (4 forcing questions, one at a time)

Dependency-ordered. Each question carries explicit "why I'm asking". Stop condition: max 4.

Q1 (root) — Product / Service

What's the product or service? Give me the name + a 1–2 sentence elevator pitch — what does it do, and who's it for?

Why I'm asking: The headline, subtext, and feature copy all derive from this. "App for productivity" produces generic boilerplate; "Async standup tool for remote engineering teams who hate Zoom" produces a landing page that converts.

Refuse mush. If user gives just a name with no pitch, push back once: "What does it do? Who's it for?" If still no pitch after push-back, deliver with explicit "generic positioning" caveat.

Q2 (depends on Q1) — Audience Register

Who's the audience? Pick one:

1. Technical buyers (engineers, ops, security)
2. Business buyers (PMs, execs, ops leaders)
3. Consumers (general public, hobbyists)
4. Internal (employees, partners — not for public sale)

Why I'm asking: Audience dictates copy register, jargon level, social-proof choices, and CTA framing. Technical buyers want specifics; consumers want benefits; internal pages can skip persuasion.

Forcing choice.

Q3 (always) — Brand Overrides

Brand colors / fonts to override the default (dark navy + teal + Inter)? Provide as: primary HEX, accent HEX, optional bg HEX. Or say "default" if you want the polished default.

Why I'm asking: The default is intentionally beautiful, but matching your brand makes the page feel native to your existing site. Even just a primary color override goes a long way.

Accept "default" or partial overrides (e.g., just primary). If only primary provided, derive accent algorithmically (lighten / darken).

Q4 (depends on Q1) — Tone

Tone — pick one:

1. Professional — confident, restrained, B2B-friendly
2. Playful — warm, light, occasional humor
3. Authoritative — expert, data-forward, trust-building
4. Minimal — terse, design-led, low copy density

Why I'm asking: Tone affects every sentence — headlines, microcopy, button text, closing copy. Picking upfront prevents tonal whiplash across sections.

Forcing choice. Recommended default: professional if Q2 = technical/business; playful if Q2 = consumer; minimal if the product is design-led.

Stop condition: After Q4, commit and generate. No follow-up questions during generation.

Content Extraction (with Fallback Strategy)

From Q1's elevator pitch, derive:

• Hero headline — punchy version of "what it does" (8–12 words)
• Hero subtext — version of "who it's for + payoff" (1–2 sentences)
• 3–6 feature bullets — distilled from pitch + audience (Q2) + tone (Q4)
• CTA text — action-oriented, matches tone
• Closing copy — short, emotive, matches tone

Fallback when input is sparse: invent compelling content from product-name semantics + audience register. Flag inferred content with a comment in the HTML source (<!-- inferred: ... -->). Don't stall waiting for more input.

Brand System Specification

Default Color Palette (Dark Navy + Teal)

:root {
  --navy:       #0A1628;
  --navy-mid:   #0D1F38;
  --teal:       #00D4AA;
  --teal-glow:  rgba(0, 212, 170, 0.12);
  --amber:      #F5A623;
  --off-white:  #F7F7F2;
  --text-muted: rgba(247, 247, 242, 0.68);
  --card-bg:    rgba(0, 212, 170, 0.06);
  --card-border:rgba(0, 212, 170, 0.15);
}

Override Pattern

When Q3 provides custom brand values, the skill substitutes them into the :root block:

Brand override:
- primary: #FF6B35    →  --navy / hero bg
- accent:  #2EC4B6    →  --teal / CTA / highlights
- bg:      #011627    →  --navy-mid / section bg
- text:    #FDFFFC    →  --off-white

If only primary provided, derive accent algorithmically (lighten 15% for accent; darken 8% for navy-mid; convert to rgba at 0.12 alpha for glow). Use scripts/brand_palette_validator.py for the deterministic derivation.

See references/brand_system_design.md for color theory + WCAG + algorithmic palette derivation canon.

Typography

• Font family: Inter (via Google Fonts)
• Weight scale: 400 (body), 500 (eyebrow), 600 (links), 700 (subtitle), 800 (H1 + H2)
• Size scale:
  • Hero H1: 68–82px
  • Section H2: 52–62px
  • Card titles: 22px
  • Body: 17–19px
  • Eyebrow: 13px (uppercase, letter-spaced)
  • CTA button: 18px (500 weight)

Components (Must Specify CSS)

• .btn-primary — CTA button with hover state (lift + brightness)
• .feature-card — card with hover lift (translateY(-6px) + border-brighten)
• .eyebrow — letter-spaced (0.2em) uppercase category label

Section 1: Hero

• min-height: 100vh, flex-centered content
• Optional eyebrow label above H1
• H1 (68–82px, 800 weight)
• Subtitle (17–19px, 1–2 sentences)
• CTA button (.btn-primary)
• Scroll-down indicator (animated chevron, CSS bounce)
• Depth layers (mouse parallax):
  • .hero-shapes-back — large blurred circles, absolute-positioned, low opacity
  • .hero-shapes-mid — smaller shapes, sharper edges, higher opacity
  • Content layer (H1 + subtitle) — moves subtly in same direction as mouse

Section 2: Features

• 3 columns default (repeat(3, 1fr) grid)
• Responsive:
  • 2 columns at 900px breakpoint
  • 1 column at 580px breakpoint
• Each card:
  • SVG icon (28px, stroke=var(--teal), no fill)
  • Title (22px, 700 weight)
  • Description (15–16px, --text-muted)
• Hover state:
  • transform: translateY(-6px)
  • border-color: var(--teal) (brighten from --card-border)
  • transition: 0.3s ease

Section 3: Closing CTA

• Full-width, background: var(--navy-mid)
• padding: 120px 24px, text-align: center
• Large closing headline (52–62px, 800 weight)
• Short subtext (--text-muted, 1–2 sentences)
• CTA button with ambient radial-gradient glow behind it:

  background: radial-gradient(circle, var(--teal-glow) 0%, transparent 70%);
  

Animation Patterns

See references/gsap_animation_patterns.md for the canon. Five patterns required:

1. Hero Entrance (GSAP timeline)

// MUST use gsap.set() FIRST to prevent FOUC
gsap.set([".eyebrow", ".hero h1", ".hero .subtitle", ".btn-primary", ".scroll-down"], {
  opacity: 0,
  y: 30
});

const tl = gsap.timeline({ defaults: { ease: "power3.out" } });
tl.to(".eyebrow", { opacity: 1, y: 0, duration: 0.6 })
  .to(".hero h1", { opacity: 1, y: 0, duration: 0.8 }, "-=0.3")
  .to(".hero .subtitle", { opacity: 1, y: 0, duration: 0.6 }, "-=0.5")
  .to(".btn-primary", { opacity: 1, y: 0, duration: 0.5 }, "-=0.3")
  .to(".scroll-down", { opacity: 1, y: 0, duration: 0.4 }, "-=0.2");

2. Mouse Parallax

const hero = document.querySelector(".hero");
hero.addEventListener("mousemove", (e) => {
  const x = (e.clientX / window.innerWidth - 0.5) * 2;
  const y = (e.clientY / window.innerHeight - 0.5) * 2;
  gsap.to(".hero-shapes-back", { x: x * 45, y: y * 22, duration: 0.8 });
  gsap.to(".hero-shapes-mid",  { x: x * 22, y: y * 11, duration: 0.8 });
  gsap.to(".hero .container",  { x: x * 8,  y: y * 5,  duration: 0.8 });
});

3. Scroll-Triggered Feature Cards

gsap.set(".feature-card", { opacity: 0, y: 55, rotateX: 18 });

ScrollTrigger.batch(".feature-card", {
  start: "top 80%",
  onEnter: batch => gsap.to(batch, {
    opacity: 1, y: 0, rotateX: 0,
    duration: 0.8,
    stagger: 0.11,
    ease: "power2.out"
  })
});

4. Floating Decorative Shapes (CSS keyframes — NOT GSAP)

CSS handles ambient continuous motion (smoother, cheaper than GSAP for indefinite animations):

@keyframes floatA {
  0%, 100% { transform: translate(0, 0) rotate(0deg); }
  50%      { transform: translate(20px, -30px) rotate(8deg); }
}
@keyframes floatB { /* different duration + rotation */ }
@keyframes floatC { /* different duration + rotation */ }

.hero-shapes-back .shape-a { animation: floatA 12s ease-in-out infinite; }

5. Scroll Indicator (CSS bounce)

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(8px); }
}
.scroll-down { animation: bounce 2s ease-in-out infinite; }

Required CDN Dependencies

<link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap" rel="stylesheet">
<script src="https://cdnjs.cloudflare.com/ajax/libs/gsap/3.12.2/gsap.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/gsap/3.12.2/ScrollTrigger.min.js"></script>

NO other external CSS or JS files. All custom CSS in <style>, all custom JS in <script> blocks within the same HTML file.

See references/single_file_html_discipline.md for the inline-only rationale.

Layout Rules

• Container max-width: 1200px, centered
• Section padding: 120px 24px (vertical 120, horizontal 24, scales down on mobile)
• Responsive breakpoints:
  • 900px → features grid 3-col → 2-col
  • 580px → all grids → 1-col; H1 scales down to ~52px
• Viewport meta: <meta name="viewport" content="width=device-width, initial-scale=1">

Output Spec

• Path: ${OUTPUT_DIR}/<product-name-kebab>.html
• Default ${OUTPUT_DIR}: ./landing-pages/
• Filename: lowercase kebab-case from product name ("Quill AI" → quill-ai.html). Use scripts/kebab_slug_generator.py for deterministic slug generation + duplicate detection.
• Self-contained: all CSS in <style>, all JS in <script>, only Google Fonts + GSAP CDN external.

Validation (Post-Generation)

Run scripts/html_validator.py --file ${OUTPUT_DIR}/<slug>.html after generation. Checks:

• All 3 required sections present (.hero, .features, .closing-cta)
• CDN deps present (Inter + GSAP + ScrollTrigger)
• gsap.set() initial states precede any gsap.timeline or gsap.to (FOUC prevention)
• Responsive breakpoints at 900px + 580px
• No external <link rel="stylesheet"> other than Google Fonts
• No external <script src=> other than GSAP CDN
• <meta name="viewport"> present
• All animated elements have initial-state declarations

Error Handling

Situation	Behavior
Input is just a name with no context	Invent compelling content from name semantics + audience register; flag as <!-- inferred --> in HTML source
Input file is large or PDF	Read fully before generating; don't truncate
Brand colors insufficient (only 1 HEX provided)	Use as primary; derive secondary/accent algorithmically (lighten/darken via brand_palette_validator.py)
Features count not specified	Default to 4
Output dir doesn't exist	Create it
Existing file at output path	Append timestamp suffix or ask user (kebab_slug_generator.py flags duplicates)
html_validator returns FAIL	Regenerate ONLY the failing sections in one targeted pass; do NOT abandon the file

Portability

• Claude Code CLI: Native — writes HTML file directly to filesystem.
• Claude.ai web: Native — produces HTML as an artifact instead of file.

Tooling

Script	Role
scripts/brand_palette_validator.py	Validates HEX format, checks WCAG AA contrast, generates derived palette from primary (algorithmic lighten/darken).
scripts/kebab_slug_generator.py	Product name → kebab-case filename + duplicate detection in output dir.
scripts/html_validator.py	Post-generation structural check: 3 sections, CDN deps, gsap.set() initial states, responsive breakpoints, no external files.

References

• references/brand_system_design.md — color theory + WCAG + algorithmic palette derivation (7+ sources)
• references/gsap_animation_patterns.md — entrance timeline + ScrollTrigger reveals + mouse parallax + CSS floats + scroll indicator (7+ sources)
• references/single_file_html_discipline.md — why inline + CDN-only externals + accessibility minimums + no-build rationale (7+ sources)

Anti-Patterns To Reject

• Hardcoded absolute paths in output directory
• Single brand palette without override documentation
• Outlining before writing — write in one pass
• External CSS or JS files (must be inline; only Google Fonts + GSAP CDN allowed)
• Skipping gsap.set() initial states (causes FOUC)
• More than 6 features in default grid (becomes unscannable)
• Brand-specific content references in the skill itself

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Version: 1.0.0 Source spec: megaprompts/04-landing-megaprompt.md Build pattern: Path B (direct conversion). Distinct from product-team/skills/landing-page-generator/.