System Requirements Document for video-downloader

1. Introduction

This document specifies the production of four original, premium, production-ready Google Play Store promotional screenshots for a Video Downloader mobile application, delivered as a single art-directed campaign set. The product intent is promotional and visual: to communicate the app's key features — fast downloads, format and quality choice, in-app playback, and organized download management — in a way that is legible at store-thumbnail size, visually consistent across all four frames, and honest about what the app actually does.

The audience is the App marketer / store listing owner who owns the Google Play Store listing for the Video Downloader app and must publish a coherent, trustworthy screenshot set that encourages installs without misleading claims, fake social proof, or borrowed branding.

The deliverable is not a new consumer app; it is the promotional screenshot set itself, presented through a first-party web surface where each of the four screenshots can be viewed and exported as a separate high-resolution PNG.

2. System Overview

2a. Product Interpretation and Delivery Boundary

The product is a four-piece promotional screenshot campaign for a Video Downloader app, plus the first-party web surface that presents, reviews, and exports those four screenshots. The screenshots are the primary artifact; the web surface exists so the store listing owner can inspect each frame at full resolution, confirm headline/supporting-text accuracy and composition, and download each PNG individually.

Delivery is first-party and anonymous. The store listing owner does not need an account to view or export the set; there is no application-owned identity, no private durable state, and no differentiated permissions. The four screenshots are the closed deliverable set — exactly four, never a combined collage — and each is exported as its own high-resolution PNG.

The current horizon covers the four screenshots and their presentation/review/export surface. Anything beyond the four specified frames (additional screenshots, localized variants, animated store assets, A/B test sets) is future work and is not part of current acceptance.

Removed from scope

• Fake ratings, fake reviews, and download counts.
• Google Play logos and copyrighted third-party brand logos.
• Misleading third-party platform branding.
• Unsupported feature claims (including any format or built-in-player claim the actual app does not support).
• A single combined collage in place of four separate screenshots.

2b. Source Content Inventory

Not applicable — no reference directive declares content_source.

2c. Page Content and Component Coverage

Landing

• Information / state: Product identity for the Video Downloader promotional screenshot set; a one-line statement of what the set is (four separate Google Play Store screenshots) and who it serves (the store listing owner); a preview strip of the four frames in order (Fast & Easy Video Downloads, Multiple Video Formats, Built-in Video Player, Smart Download Manager).
• Primary action: Enter the screenshot set (go to Screenshots).
• Supporting actions: Jump directly to Screenshot Review; open any single frame preview.
• Domain entities: Screenshot set (four frames), frame title, frame headline, frame supporting text.
• Component responsibilities: Hero block carrying the campaign identity and the diagonal headline-to-phone composition; four-frame preview strip with per-frame title chips; entry controls to Screenshots and Screenshot Review.
• States: Loading (preview thumbnails resolving); empty (not applicable — the set is fixed at four); success (all four previews render); error (a preview fails to load → placeholder frame with retry); recovery (retry reloads the failed preview without losing position).

Screenshots

• Information / state: The four separate screenshots, each shown at full resolution with its exact headline and supporting text:
  • Screenshot 1 — "Download Videos in Seconds" / "Save your favorite videos quickly and easily."
  • Screenshot 2 — "Your Videos, Your Format" / "Choose the format and quality that suits you."
  • Screenshot 3 — "Watch Anytime, Anywhere" / "Enjoy your downloaded videos in one place."
  • Screenshot 4 — "All Your Downloads. One Place." / "Manage, organize, and access your saved videos easily."
• Primary action: Download an individual screenshot as a high-resolution PNG.
• Supporting actions: Move between the four frames; open a frame in Screenshot Review.
• Domain entities: Screenshot (frame number, title, headline, supporting text, PNG asset, resolution).
• Component responsibilities: Frame viewer with per-frame headline/supporting-text caption; per-frame PNG download control; frame navigation; asset metadata (resolution, format).
• States: Loading (PNG resolving); empty (not applicable); success (frame renders crisply at full resolution with download available); error (asset unavailable → inline message with retry, other frames remain usable); recovery (retry re-fetches only the failed asset).

Screenshot Review

• Information / state: A focused per-frame review view presenting each screenshot's headline, supporting text, and mockup composition for verification before finalizing the set; a checklist of the binding constraints (four separate frames, consistent palette/typography/phone frame/lighting, safe margins, no fake ratings/reviews/download counts, no Google Play or third-party logos, no unsupported format or player claims, green only for completed/confirmed states).
• Primary action: Confirm a frame as reviewed.
• Supporting actions: Flag a frame for revision with a note; return to Screenshots to re-export.
• Domain entities: Review record (frame reference, review status, note), constraint checklist item.
• Component responsibilities: Frame-by-frame review panel; constraint checklist with per-item pass/fail; review status indicator; note field for flagged frames.
• States: Loading (review data resolving); empty (no frames reviewed yet → all four listed as pending); success (frame marked reviewed, status reflected); error (save fails → status retained as pending with retry); recovery (retry re-submits the review action).

3. Functional Requirements

FR-1 — Four separate screenshots, not a collage As the App marketer / store listing owner, I should receive four separate, complete promotional screenshots rather than one combined collage, so that each can be uploaded as an individual store listing image.

• Provenance: explicit.
• Lifecycle: Trigger — the set is produced. Result — four distinct frames exist as separate assets. Failure/recovery — if frames are merged into one image, the set is rejected and re-exported as four. Continuation — each frame proceeds to review and export.
• Acceptance: Exactly four separate image assets exist; no combined collage asset is delivered.

FR-2 — Screenshot 1 headline and supporting text As the App marketer / store listing owner, I should see Screenshot 1 carry the headline "Download Videos in Seconds" and the supporting text "Save your favorite videos quickly and easily.", so that the fast-download message is exact.

• Provenance: explicit.
• Acceptance: Headline and supporting text match character-for-character.

FR-3 — Screenshot 1 visual composition As the App marketer / store listing owner, I should see Screenshot 1 show a large, angled smartphone mockup displaying a clean video downloader interface with a URL input field, a prominent blue Download button, a video thumbnail, and a download progress indicator, plus subtle speed lines, glowing blue accents, and floating download-arrow elements, so that speed is communicated at a glance.

• Provenance: explicit.
• Acceptance: All named elements are present; the phone is angled and dominant; speed lines, blue glow, and floating download-arrow marks are visible.

FR-4 — Screenshot 2 headline and supporting text As the App marketer / store listing owner, I should see Screenshot 2 carry the headline "Your Videos, Your Format" and the supporting text "Choose the format and quality that suits you.", so that the format-choice message is exact.

• Provenance: explicit.
• Acceptance: Headline and supporting text match character-for-character.

FR-5 — Screenshot 2 visual composition As the App marketer / store listing owner, I should see Screenshot 2 show a realistic smartphone UI with video quality options such as 360p, 480p, 720p, and 1080p, along with MP4 and other formats only if supported by the actual app, surrounded by elegant floating format cards and resolution badges, so that format and quality choice is simple to understand.

• Provenance: explicit.
• Acceptance: 360p, 480p, 720p, and 1080p appear as quality options; MP4 and any other format appear only where the actual app supports them; floating format cards and resolution badges are present; the interface reads as simple.

FR-6 — Screenshot 3 headline and supporting text As the App marketer / store listing owner, I should see Screenshot 3 carry the headline "Watch Anytime, Anywhere" and the supporting text "Enjoy your downloaded videos in one place.", so that the playback message is exact.

• Provenance: explicit.
• Acceptance: Headline and supporting text match character-for-character.

FR-7 — Screenshot 3 visual composition (conditional on actual player) As the App marketer / store listing owner, I should see Screenshot 3 show a polished in-app video player interface with a large video preview, play/pause controls, a progress bar, and a clean media library screen, using cinematic thumbnail imagery, subtle lighting, and a premium dark interface — only if the app actually has a built-in player.

• Provenance: explicit.
• Constraint: The built-in player feature is included only if the app actually has one; if it does not, this frame must not claim it.
• Acceptance: When the app has a built-in player, all named player elements are present; when it does not, no built-in-player claim appears.

FR-8 — Screenshot 4 headline and supporting text As the App marketer / store listing owner, I should see Screenshot 4 carry the headline "All Your Downloads. One Place." and the supporting text "Manage, organize, and access your saved videos easily.", so that the download-management message is exact.

• Provenance: explicit.
• Acceptance: Headline and supporting text match character-for-character.

FR-9 — Screenshot 4 visual composition As the App marketer / store listing owner, I should see Screenshot 4 show an organized downloads screen with video thumbnails, file names, download statuses, file sizes, and completed-download indicators, with a clear visual distinction between downloading and completed files, so that download management reads as clean and uncluttered.

• Provenance: explicit.
• Acceptance: All named data elements are present; downloading vs. completed is visually distinct; layout is uncluttered.

FR-10 — Overall style As the App marketer / store listing owner, I should see the set rendered in a modern, premium, clean, tech-focused, and user-friendly style with portrait mobile store screenshot layouts, bold headlines, realistic smartphone UI mockups, and polished promotional compositions.

• Provenance: explicit.
• Acceptance: All four frames are portrait store-screenshot layouts with bold headlines and realistic phone mockups.

FR-11 — Color palette As the App marketer / store listing owner, I should see a deep navy or dark charcoal ground combined with electric blue, vibrant purple gradients, and white typography, with green used only for successful downloads or confirmation states.

• Provenance: explicit.
• Acceptance: Palette matches; green appears only on completed/confirmed states.

FR-12 — Typography As the App marketer / store listing owner, I should see bold, modern sans-serif fonts with clear hierarchy and excellent readability.

• Provenance: explicit.
• Acceptance: Headlines and supporting text use bold modern sans-serif with a clear hierarchy.

FR-13 — Realistic mobile UI As the App marketer / store listing owner, I should see realistic mobile application interfaces with clean layouts, intuitive icons, download progress indicators, video thumbnails, and organized lists.

• Provenance: explicit.
• Acceptance: Each frame's in-phone UI shows the named interface elements.

FR-14 — Visual quality As the App marketer / store listing owner, I should see high-resolution, crisp details, professional spacing, balanced composition, and a consistent visual identity across all four screenshots.

• Provenance: explicit.
• Acceptance: All four frames are high-resolution, crisply detailed, and share one visual identity.

FR-15 — Originality As the App marketer / store listing owner, I should see all graphics and UI elements be original, with no copying of existing apps, trademarks, logos, or promotional layouts.

• Provenance: explicit.
• Acceptance: No element reproduces an existing app, trademark, logo, or promotional layout.

FR-16 — Consistency across the set As the App marketer / store listing owner, I should see the same color palette, typography, phone frame, lighting style, and visual language throughout all four screenshots.

• Provenance: explicit.
• Acceptance: Palette, type, phone frame, lighting, and visual language are identical across frames.

FR-17 — Headline legibility As the App marketer / store listing owner, I should see headlines kept large, short, and readable at mobile size.

• Provenance: explicit.
• Acceptance: Each headline is short and remains legible at store-thumbnail scale.

FR-18 — Phone as focal point As the App marketer / store listing owner, I should see the smartphone UI positioned as the main visual focus in every frame.

• Provenance: explicit.
• Acceptance: The phone mockup is the dominant object in each frame.

FR-19 — Safe margins As the App marketer / store listing owner, I should see safe margins maintained with no important text placed near the edges.

• Provenance: explicit.
• Acceptance: Headlines and supporting text sit inside the safe margin in every frame.

FR-20 — Store-listing authenticity As the App marketer / store listing owner, I should see the design read as a real Google Play Store listing rather than a generic advertising poster.

• Provenance: explicit.
• Acceptance: Frames read as store listing screenshots, not generic posters.

FR-21 — Separate high-resolution PNG export As the App marketer / store listing owner, I should be able to export each screenshot as a separate high-resolution PNG.

• Provenance: explicit.
• Lifecycle: Trigger — the owner selects a frame and exports. Result — a separate high-resolution PNG is produced for that frame. Failure/recovery — if export fails, the owner retries without losing the frame selection. Continuation — the owner proceeds to the next frame.
• Acceptance: Four separate PNG files exist, each high-resolution.

FR-22 — Final deliverable set As the App marketer / store listing owner, I should receive four original, polished, production-ready Google Play Store promotional screenshots.

• Provenance: explicit.
• Acceptance: Four original, polished, production-ready frames are delivered.

FR-23 — View and download each screenshot As the App marketer / store listing owner, I should view each of the four screenshots individually at full resolution and download it as a PNG from the Screenshots page.

• Provenance: required_inference.
• Lifecycle: Trigger — the owner opens Screenshots. Result — each frame renders at full resolution with a download control. Failure/recovery — a failed asset shows an inline error with retry while other frames stay usable. Continuation — the owner moves to the next frame or to review.
• Acceptance: Each frame is individually viewable and individually downloadable.

FR-24 — Review each frame before finalizing As the App marketer / store listing owner, I should review each screenshot's headline, supporting text, and mockup composition against the binding constraints before finalizing the set.

• Provenance: required_inference.
• Lifecycle: Trigger — the owner opens Screenshot Review. Result — each frame shows its headline, supporting text, composition, and constraint checklist with a review status. Failure/recovery — a failed save keeps the frame pending with retry. Continuation — the owner confirms or flags each frame.
• Acceptance: Each frame can be marked reviewed or flagged with a note; status is observable.

4. User Personas

App marketer / store listing owner

• Product context: Owns the Google Play Store listing for the Video Downloader app. Needs a consistent, premium set of four promotional screenshots that communicate the app's key features and encourage installs.
• Primary goal: Publish four original, polished, production-ready screenshots that read as one art-directed campaign and make no false claims.
• Distinct responsibilities: Verifies each frame's exact headline and supporting text; checks visual consistency (palette, typography, phone frame, lighting); confirms safe margins and headline legibility at mobile size; confirms the absence of fake ratings, reviews, download counts, Google Play logos, and third-party brand logos; confirms that format and built-in-player claims match what the app actually supports; exports each frame as a separate high-resolution PNG.
• Inputs and decisions: The four frame specifications; the actual app's supported formats and whether it has a built-in player; the constraint checklist; the decision to confirm or flag each frame.
• Interactions with other participants: None beyond the owner — the set is produced for the owner's own listing, with no counterparty, recipient, or approver in the accepted scope.
• Observable success: Four separate high-resolution PNGs, each carrying its exact headline and supporting text, sharing one visual identity, passing the constraint checklist, and free of prohibited claims and branding.

5. Core User Flows

Flow A — Understand the set and enter it

1. The store listing owner opens Landing anonymously.
2. Landing states what the set is (four separate Google Play Store screenshots for the Video Downloader app) and shows a preview strip of the four frames in order.
3. The owner selects Screenshots to inspect the set, or Screenshot Review to go straight to verification.
4. Observable result: the owner knows the set is four separate frames and where to inspect or review them.

Flow B — Inspect and export each screenshot

1. The owner opens Screenshots.
2. The owner selects a frame; it renders at full resolution with its exact headline and supporting text as caption.
3. The owner inspects the composition against the frame's visual direction (e.g., Screenshot 1: angled phone, URL input, blue Download button, thumbnail, progress indicator, speed lines, glow, floating arrows).
4. The owner selects Download PNG for that frame; a separate high-resolution PNG is produced.
5. If an asset fails to load, an inline error appears with Retry; other frames remain usable, and retry re-fetches only the failed asset.
6. The owner repeats for the remaining frames.
7. Observable result: four separate high-resolution PNGs, one per frame.

Flow C — Review each frame before finalizing

1. The owner opens Screenshot Review.
2. For each frame, the owner sees the headline, supporting text, mockup composition, and the constraint checklist (four separate frames; consistent palette/typography/phone frame/lighting; safe margins; no fake ratings/reviews/download counts; no Google Play or third-party logos; no unsupported format or player claims; green only for completed/confirmed states).
3. The owner marks the frame Reviewed, or Flags it with a note for revision.
4. If saving the review status fails, the frame stays pending and the owner retries.
5. For a flagged frame, the owner returns to Screenshots to re-export after revision, then re-reviews.
6. Observable result: every frame carries an observable review status; the set is finalized only when all four are reviewed.

Flow D — Conditional handling of the built-in player frame

1. The owner confirms whether the actual app has a built-in video player.
2. If it does, Screenshot 3 is produced with the in-app player interface (large preview, play/pause, progress bar, media library) per Flow B.
3. If it does not, Screenshot 3 must not claim a built-in player; the frame is revised accordingly and re-reviewed per Flow C.
4. Observable result: no unsupported built-in-player claim appears in the finalized set.

6. Visuals Colors and Theme

Muse and headline: Gleb Kuznetsov — Cinematic future tech for downloads that feel instant.

Mode: Dark throughout. No light ground in any frame.

Color tokens (exact hex by role):

• Background ground: #0A0E1A (deep navy-charcoal) — all four frames.
• Raised surface / glass panel: #141A2E.
• Primary text (headlines, primary UI labels): #FFFFFF.
• Primary accent (Download button, progress fills, resolution badges, glow): #2E7BFF (electric blue).
• Secondary accent (blue→purple gradient sweeps, format-card edges): #A855F7 (violet).
• Muted text (supporting copy, metadata): #8A94B8.
• Success only (completed-download checkmarks, "Done" states): #22C55E — never a brand color.
• Hairline borders: white at 12% opacity (rgba(255,255,255,0.12)).

Balance: ~70% dark ground, ~20% phone UI surface, ~10% glow/accents.

Typography:

• Headings: Space Grotesk 700, tracking −0.03em, sentence case for the four big headlines; uppercase permitted only for micro-labels.
• Body and in-phone UI copy: Manrope 500/600, roomy line-height.
• Numerals (file sizes, percentages, resolution values): Space Grotesk tabular figures, treated as HUD data.
• Scale (1.333 modular): headline 64px mobile → 96px desktop; inside the 1080×1920 store canvas 96–120px; supporting 22–26px; panel titles 28px; UI labels 16–18px; micro-labels 12px uppercase at 0.14em tracking.
• Headlines set very large with a hard two-line break, reading as a stacked block.

Shape language: Glassy rounded panels with 1px luminous hairline borders over dark grounds; the phone frame is a soft continuous-curve slab with a thin electric-blue rim light; floating format cards and badges are rounded rectangles at 20–24px radius with a blurred glow beneath. Thin luminous strokes, radial rings, and arcs echo download progress. No hard drop shadows — glow replaces shadow.

Layout: Portrait 1080×1920 (9:16) canvases. Shared skeleton: 96px safe margin; headline block anchored top-left in two stacked lines; supporting line beneath; phone mockup dominant in the lower 60–70% of the frame, angled 6–10° and bleeding slightly off the bottom edge; HUD-style floating panels orbit the phone left and right and never cross the headline; a faint radial glow behind the phone is the single light source.

Imagery: No stock people, no third-party logos. Cinematic abstract video thumbnails inside the phone UI — aurora, landscape, and neon-city frames generated as original gradients and geometric scenes, each with a small duration chip and play glyph. Original luminous download-arrow glyphs, progress arcs, particle dust, and volumetric glow are the only decorative imagery; all icons drawn from one original set.

Avoid: Centered headline + subtext + button SaaS hero layouts; blue-on-white or any light ground; grids of identical hover-lift cards or generic dashboard tiles; stock photography of people, third-party platform logos, fake ratings or download counts; green anywhere except completed/confirmed states; Inter, Roboto, Arial, Poppins, or system-ui for headlines or body; gradient-blob decoration not tied to the single phone light source; bouncy or playful motion.

7. Signature Design Concept

The public entry (Landing) is built as Screenshot 1's hero frame brought to life: a deep navy-charcoal full-bleed ground with a single volumetric blue-to-violet glow blooming from behind a large phone tilted ~8° and cropped at the bottom edge. The phone screen shows the downloader UI — URL input pill, a solid electric-blue Download button, a cinematic thumbnail with a progress ring frozen at 68% — while three original glow-arrow glyphs and two thin speed lines streak past it. The headline "Download Videos in Seconds" sits top-left in two stacked lines of oversized Space Grotesk white, with the supporting line in muted blue-grey beneath. Nothing is centred; the composition is a diagonal from headline (top-left) to phone (bottom-right).

The same signature moves carry into the preview strip and the Screenshots page: every frame keeps the oversized two-line white headline top-left, the tilted phone bleeding off the bottom edge, a 1px electric-blue/violet hairline plus soft outer glow on the phone rim, HUD-style floating glass panels with tabular numerals, progress captured mid-motion at 68% in electric blue, and green checkmarks only on completed rows in Screenshot 4. The four frames read as one campaign because they share the same diagonal, the same single light source, and the same luminous vector marks.

8. Interaction Model & Motion Direction

Interaction Model: Animated Motion Tempo: cinematic Hero Dimensionality: webgl

Landing Hero Motion Brief

• Focal subject: The tilted phone mockup with its downloader UI (URL pill, electric-blue Download button, cinematic thumbnail with a 68% progress ring), lit by a single volumetric blue-to-violet glow behind it.
• Input → transformation → outcome thesis: As the visitor arrives and scrolls, the camera drifts slowly across the composition; the light sweep travels along the phone rim, the progress ring holds at 68%, and the glow-arrow glyphs and speed lines trail the phone at the headline's diagonal. The outcome is a composed, cinematic first frame that resolves into the four-frame preview strip — no new behavior, only the accepted content and states recomposed.
• Motion vocabulary: Slow continuous parallax between phone, glow, and floating panels; scroll-scrubbed camera drift; light sweep across the rim; progress arcs captured mid-fill; speed-line streaks. Nothing bouncy, nothing playful.
• Composed first frame: Headline top-left in two stacked lines, supporting line beneath, phone bottom-right tilted ~8° and cropped at the bottom edge, glow behind the phone, three glow-arrow glyphs and two speed lines streaking past.
• Reduced-motion state: All layers settle into a static composed arrangement with the same hierarchy — headline, supporting line, phone, glow, and floating panels in their final positions, with no parallax, sweep, or drift.

Landing Hero 3D Scene Brief — DIRECTION-DERIVED

One crafted real-time scene: a soft continuous-curve phone slab tilted ~8°, its screen a live-rendered downloader UI (URL pill, electric-blue Download button, cinematic thumbnail, progress ring held at 68%), lit by a single volumetric blue-to-violet glow behind it, with three luminous download-arrow glyphs and two thin speed lines as original vector marks at the headline's diagonal. The scene shows the product's defining state — a download in progress, fast and controlled — and holds it cinematically rather than animating new behavior. Reduced-motion renders the same scene as a static composed frame.

9. Non-Functional Requirements

• Resolution and export: Each screenshot is exported as a separate high-resolution PNG on a 1080×1920 portrait canvas. Provenance: explicit. Rationale: store listing requirement and the user's export instruction.
• Legibility at thumbnail scale: Headlines remain large, short, and readable at mobile/store-thumbnail size; supporting text stays legible. Provenance: explicit.
• Safe margins: A 96px safe margin is maintained; no important text sits near the edges. Provenance: explicit.
• Visual consistency: Identical palette, typography, phone frame, lighting style, and visual language across all four frames. Provenance: explicit.
• Originality and IP safety: All graphics and UI elements are original; no copied apps, trademarks, logos, or promotional layouts; no copyrighted brand logos or misleading third-party platform branding. Provenance: explicit.
• Truthfulness: No fake ratings, fake reviews, download counts, Google Play logos, or unsupported feature claims; MP4 and other formats shown only if supported by the actual app; the built-in player shown only if the app actually has one. Provenance: explicit.
• Color discipline: Green appears only for successful downloads or confirmation states. Provenance: explicit.
• Readable text and controls stay whole: At 375px, 768px, and 1280px, headlines, labels, numbers, cards' text, and controls stay entirely inside the viewport and their container, wrapping or scaling (e.g., clamp()) to fit, with no other element covering them. Imagery and decoration may crop, bleed, rotate, or overlap as the direction asks, provided they cover no readable text or control. Provenance: explicit (design constraint).
• Reduced motion: With prefers-reduced-motion, the hero and any moving content provide a usable static arrangement with the same hierarchy. Provenance: explicit (design constraint).

10. Tech Stack

• Frontend: React application UI presenting Landing, Screenshots, and Screenshot Review, with the WebGL/R3F hero scene on Landing per the creative direction.
• Backend: Shared FastAPI process for application APIs and domain modules (screenshot asset metadata, review status).
• Database: MariaDB for application-owned persistent data (screenshot asset records and review status).
• Infrastructure: Docker / docker-compose for the frontend, backend, and database services.

11. Assumptions and Constraints

• Assumption: The actual Video Downloader app's supported formats and whether it has a built-in player are known to the store listing owner and govern Screenshots 2 and 3. Labeled required_inference; the frames must not claim unsupported features.
• Assumption: The four screenshots are the complete current deliverable; no additional frames, localized variants, or animated store assets are in current scope.
• Constraint: Exactly four separate screenshots — never a combined collage.
• Constraint: No fake ratings, reviews, download counts, Google Play logos, copyrighted brand logos, misleading third-party branding, or unsupported feature claims.
• Constraint: Green only for successful downloads or confirmation states.
• Constraint: All graphics and UI elements original; no copied apps, trademarks, logos, or promotional layouts.
• Constraint: Same palette, typography, phone frame, lighting style, and visual language across all four frames.
• Constraint: Safe margins; headlines large, short, and readable at mobile size; phone UI as the main visual focus.
• Constraint: Each screenshot exported as a separate high-resolution PNG.
• Access: The presentation surface is anonymous; no account, private durable state, or differentiated permissions are required.

12. Glossary

• Store listing owner: The App marketer persona who owns the Google Play Store listing and publishes the screenshot set.
• Screenshot set: The four separate promotional frames delivered as one campaign.
• Frame: One of the four individual screenshots (Screenshot 1–4).
• Safe margin: The 96px inset keeping important text away from frame edges.
• HUD panel: A floating glass panel orbiting the phone, carrying data such as URL, progress, resolution badges, or file status.
• Progress ring: A circular indicator capturing download progress mid-fill (held at 68% in the direction).
• High-resolution PNG: The separate per-frame export format for the store listing.
• Built-in player: The app's in-app video playback feature, shown in Screenshot 3 only if the app actually has one.