# Prompt: Scrollytelling Data Story

**Objective:** Create a single-file HTML interactive scrollytelling visualization.

**Requirements:**
1.  **Topic:** The evolution of global temperature anomalies (simulated data from 1880 to 2050).
2.  **Layout:** A two-column scrollytelling layout (or stacked on mobile) using native `position: sticky` for the graphic.
3.  **Scenes (Steps):**
    *   *Intro:* Setting the scene.
    *   *Step 1 (The Baseline):* Show flat-ish data pre-1950.
    *   *Step 2 (The Acceleration):* Zoom out to show 1950-2000, revealing an upward trend.
    *   *Step 3 (The Modern Crisis):* Show data up to 2024, highlighting the sharp spikes.
    *   *Step 4 (Divergent Futures):* Show projected scenarios to 2050 (mitigation vs. status quo).
4.  **Technology:**
    *   No external assets (images, CSS files) except CDNs for scripts.
    *   Use D3.js (via CDN) for robust chart drawing and transitions.
    *   Use `IntersectionObserver` to trigger chart transitions seamlessly.
5.  **Design:** High-quality editorial design. Dark mode, stark accent colors, clear typography, and fluid SVG transitions.

**Constraints:**
- Must reside entirely in `index.html`.
- No image dependencies.
- Fully responsive.