Lauberhorn Ridge — Référence de design web et prompt

# Prompt: Lauberhorn Ridge trail dashboard hero

Build a single-file, one-screen **hiking trail guide dashboard hero** for a fictional alpine trail, **Lauberhorn Ridge** (above Interlaken, Switzerland), seen by a signed-in hiker, **Mira Holt**. Use plain HTML, CSS and vanilla JS, with no framework and no build step. The look is a bright autumn travel app: a full-bleed photo of a golden larch valley with a turquoise lake under snowy peaks, and soft cream glass widgets floating over it.

## Scene

- **Plate:** the whole background is ONE 16:10 photo (1728×1080), stretched to the frame: `https://d2ol7oe51mr4n9.cloudfront.net/user_38xzZboKViGWJOttwIXH07lWA1P/4e84f7cd-8250-48e6-8dfa-746b13b73bfb.jpg`.
  - Golden larch forest on both slopes, a turquoise glacial lake winding into the valley, snow-capped peaks and a clear blue sky at the top.
- **Motion:** a muted looping drone shot of the same valley plays over it: `https://d2ol7oe51mr4n9.cloudfront.net/user_38xzZboKViGWJOttwIXH07lWA1P/48d4c209-86b6-4b1c-b972-4f57e3dafe89.mp4` (1280×720, 10s, loops seamlessly because it plays forward then reversed). The camera glides forward over the larches toward the lake, with a slow push-in and slight parallax.
  - The video was rendered 16:9 from the plate mirror-padded 96/1728 on each side. Lay it at **111.11% width, left −5.556%** so its middle sits exactly on the plate.
  - Fade it in (0.8s) once its first frame is ready.
- **Rule:** nothing in the scene is drawn or animated in code. Only the UI animates.