A deep-space ambient atmosphere for claude.ai — animated starfield backgrounds, glassmorphism panels, and focus tools. Built for the aesthetic, zero bloat.
- Animated nebula background — slow-drifting gradient layers, no external images
- Custom background — paste any image/video URL or upload a local file (up to 15MB)
- Star field — 480 deterministic stars (stable across reloads, no flickering)
- Particle system — floating ambient embers, pure CSS, GPU-accelerated
- Glassmorphism panels — sidebar, header, input, modals all go frosted-glass
- Per-element opacity — independent depth control for sidebar, chat area, and input bar
- 4 themes — Void (cyan), Nebula (purple), Neon (vivid cyan), Mono (slate)
- Code block styling — syntax-highlighted code blocks themed to match your active theme
- Focus mode — hides conversation history until you hover the sidebar
- Compact mode — tighter message spacing for more content density
- Glow accents — subtle neon glow on interactive elements
- Grid lines — optional HUD overlay
- Composer style — Glass, Neon, or Default input area styling
- Custom CSS — inject your own CSS directly into claude.ai
- Keyboard shortcut —
Alt+Shift+Ntoggles Nebula on/off instantly - Animation speed — Slow / Medium / Off
- SPA-aware — survives Next.js navigation without breaking
- Private — no network calls, no analytics; settings sync via
chrome.storage.sync
- Download nebula-for-claude-v1.1.1.zip
- Extract the zip anywhere
- Open Chrome →
chrome://extensions - Enable Developer mode (top right)
- Click Load unpacked → select the extracted folder
- Pin from the puzzle icon → open claude.ai
git clone https://github.com/Python840/nebula-for-claude-.gitThen follow steps 3–6 above.
Chrome Web Store release planned.
| Name | Base | Accent | Vibe |
|---|---|---|---|
| Void | #020817 |
cyan | Deep space, Nano City |
| Nebula | #05020f |
purple | Galactic, atmospheric |
| Neon | #010a10 |
vivid cyan | Electric, high-contrast |
| Mono | #0a0a0f |
indigo | Minimal, clean |
"permissions": ["storage"],
"host_permissions": ["https://claude.ai/*"]- storage — remembers your settings across sessions
- host_permissions — runs only on claude.ai
No data leaves your machine.
- Injects a fixed
<div id="nebula-bg">behind claude.ai's#__nextcontainer - Adds CSS classes to
<html>to trigger glassmorphism on structural elements - Star field is generated via a deterministic LCG sequence (seeded, not random) — same stars every load
- Patches
history.pushState/replaceStateto survive SPA navigation - All settings stored in
chrome.storage.sync— syncs across devices
MIT — do anything, keep the notice.
Maintained with Claude.