Loopstack — Référence de design web et prompt

# Recreate this site as a single HTML file: Loopstack

You are an expert creative front-end developer. Produce a **single self-contained `index.html`** that reproduces the project below **exactly** — same layout, sections, visuals, motion, and interaction. Pure HTML/CSS/JS in one file: no build step, no framework, no bundler. You may inline all CSS in a `<style>` tag and all JS in a `<script>` tag at the end of `<body>`. Load fonts from their CDNs. Hardcode every value given here as a fixed constant. Rebuild each component described below as a section of the one file.

## What it is

A full-viewport, single-screen "footer hero" landing moment on a pure black background. A looping flower video fills the bottom 90% of the screen, with a soft black radial gradient bleeding in from the top to fade the video into the page. Centered near the top is a serif headline and a pill "Book a demo" button with a pulsing neon-green status dot. A fixed footer block sits centered at the vertical middle of the screen ("Stay in Touch" / "Think. Build. Repeat." over a thin divider, with social icons, nav links, and a copyright). A massive "Loopstack" wordmark is pinned across the very bottom. On load: the headline reveals word-by-word (slide up + un-blur from a mask) and the giant wordmark reveals letter-by-letter (slide in from the left + un-blur). A custom cursor follows the pointer — an outlined ring that tracks instantly plus a lagging glassmorphism pill reading "SAY HELLO!"; hovering the button hides the pill and expands the ring. The page does not scroll (it is one fixed screen). Everything is white text on black with a single neon-green accent `#39FF14`.

## Page shell & libraries

- No JS libraries. Everything is hand-rolled vanilla JS + CSS.
- `<html lang="ru">`, `<head>` with `<meta charset="UTF-8">` and `<meta name="viewport" content="width=device-width, initial-scale=1.0">`, `<title>Loopstack</title>`.