diff --git a/favicon.svg b/favicon.svg
index 976ca42..4ebff3b 100644
--- a/favicon.svg
+++ b/favicon.svg
@@ -1 +1,8 @@
-<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64"><rect width="64" height="64" rx="14" fill="#0b0b0e"/><g fill="none" stroke="#e9d8a6" stroke-width="2"><circle cx="32" cy="32" r="24" opacity=".3"/><circle cx="32" cy="32" r="16" opacity=".6"/></g><circle cx="32" cy="32" r="6" fill="#e9d8a6"/></svg>
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64">
+  <style>line{stroke:#ededf0}@media (prefers-color-scheme:light){line{stroke:#17171a}}</style>
+  <g transform="translate(32 32)" stroke-width="9" stroke-linecap="butt">
+    <line x1="0" y1="-27" x2="0" y2="27"/>
+    <line x1="-23.4" y1="-13.5" x2="23.4" y2="13.5"/>
+    <line x1="-23.4" y1="13.5" x2="23.4" y2="-13.5"/>
+  </g>
+</svg>
diff --git a/icons/icon.html b/icons/icon.html
new file mode 100644
index 0000000..e890749
--- /dev/null
+++ b/icons/icon.html
@@ -0,0 +1,5 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>icon</title>
+<style>html,body{margin:0;height:100%;background:#0b0b0e;overflow:hidden}img{display:block;width:100vmin;height:100vmin}</style>
+<img src="icon.svg" alt="">
diff --git a/icons/icon.svg b/icons/icon.svg
new file mode 100644
index 0000000..fa854cd
--- /dev/null
+++ b/icons/icon.svg
@@ -0,0 +1,8 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512">
+  <rect width="512" height="512" fill="#0b0b0e"/>
+  <g transform="translate(256 256)" stroke="#ededf0" stroke-width="58" stroke-linecap="butt">
+    <line x1="0" y1="-150" x2="0" y2="150"/>
+    <line x1="-130" y1="-75" x2="130" y2="75"/>
+    <line x1="-130" y1="75" x2="130" y2="-75"/>
+  </g>
+</svg>
diff --git a/manifest.json b/manifest.json
new file mode 100644
index 0000000..6af38ba
--- /dev/null
+++ b/manifest.json
@@ -0,0 +1,16 @@
+{
+  "name": "gandora",
+  "short_name": "gandora",
+  "description": "Type a seed. Get a station. Every song is made for you as it plays.",
+  "start_url": "/",
+  "scope": "/",
+  "display": "standalone",
+  "orientation": "portrait",
+  "background_color": "#0b0b0e",
+  "theme_color": "#0b0b0e",
+  "icons": [
+    { "src": "icons/icon.svg", "sizes": "any", "type": "image/svg+xml", "purpose": "any maskable" },
+    { "src": "icons/icon-192.png", "sizes": "192x192", "type": "image/png", "purpose": "any maskable" },
+    { "src": "icons/icon-512.png", "sizes": "512x512", "type": "image/png", "purpose": "any maskable" }
+  ]
+}
diff --git a/sw.js b/sw.js
new file mode 100644
index 0000000..2ca8288
--- /dev/null
+++ b/sw.js
@@ -0,0 +1,13 @@
+// gandora's service worker: the shell is cached so the app opens and the library plays with no signal.
+// Tracks live in IndexedDB already; the DJ and new renders need the network and the page says so.
+const SHELL = "gandora-shell-v1";
+const FILES = ["/", "/index.html", "/brain.js", "/favicon.svg", "/manifest.json", "/icons/icon.svg"];
+self.addEventListener("install", (e) => { e.waitUntil(caches.open(SHELL).then((c) => c.addAll(FILES)).then(() => self.skipWaiting())); });
+self.addEventListener("activate", (e) => { e.waitUntil(caches.keys().then((ks) => Promise.all(ks.filter((k) => k !== SHELL).map((k) => caches.delete(k)))).then(() => self.clients.claim())); });
+// same-origin GETs: network first (so a deploy shows up on the next open), cache as the fallback; everything else untouched
+self.addEventListener("fetch", (e) => {
+  const u = new URL(e.request.url);
+  if (e.request.method !== "GET" || u.origin !== location.origin) return;
+  e.respondWith(fetch(e.request).then((r) => { if (r.ok) caches.open(SHELL).then((c) => c.put(e.request, r.clone())); return r; })
+    .catch(() => caches.match(e.request, { ignoreSearch: true }).then((r) => r || caches.match("/"))));
+});