diff --git a/index.html b/index.html
index 74883f5..77c5869 100644
--- a/index.html
+++ b/index.html
@@ -12,8 +12,15 @@
     />
     <title>Cave Survey Viewer</title>
     <meta name="google-site-verification" content="yhJBw46UtDk7-YZn_gDqYoYJpHEHPOMHRE065-Nohf4" />
+    <!-- Favicons: SVG first so capable browsers render a sharp, scalable icon;
+         PNG/ICO fallbacks for older browsers and platform-specific surfaces. -->
+    <link rel="icon" href="/favicon.svg" type="image/svg+xml" />
+    <link rel="icon" href="/favicon.ico" sizes="any" />
+    <link rel="icon" type="image/png" sizes="48x48" href="/favicon-48x48.png" />
     <link rel="icon" type="image/png" sizes="96x96" href="/favicon-96x96.png" />
-    <link rel="icon" type="image/png" href="/favicon.png" />
+    <link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png" />
+    <link rel="manifest" href="/site.webmanifest" />
+    <meta name="theme-color" content="#121a28" />
     <meta name="application-name" content="Cave Survey Viewer" />
     <meta
       name="description"
diff --git a/public/android-chrome-192x192.png b/public/android-chrome-192x192.png
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diff --git a/public/android-chrome-512x512.png b/public/android-chrome-512x512.png
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diff --git a/public/apple-touch-icon.png b/public/apple-touch-icon.png
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index 0000000..47ee316
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diff --git a/public/favicon-48x48.png b/public/favicon-48x48.png
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diff --git a/public/favicon-96x96.png b/public/favicon-96x96.png
index c4bb6e0..65dc247 100644
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diff --git a/public/favicon.ico b/public/favicon.ico
new file mode 100644
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diff --git a/public/favicon.png b/public/favicon.png
deleted file mode 100644
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diff --git a/public/favicon.svg b/public/favicon.svg
new file mode 100644
index 0000000..9555cf8
--- /dev/null
+++ b/public/favicon.svg
@@ -0,0 +1,11 @@
+<svg width="48" height="48" viewBox="0 0 48 48" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Cave Survey Viewer">
+  <rect width="48" height="48" rx="10" fill="#121a28"/>
+  <g fill="none" stroke="#33d6c0" stroke-width="3.1" stroke-linejoin="round" stroke-linecap="round">
+    <polygon points="24,3 42.19,13.5 42.19,34.5 24,45 5.81,34.5 5.81,13.5"/>
+    <path d="M5.81 13.5 L24 24 L42.19 13.5 M24 24 L24 45"/>
+  </g>
+  <path d="M14 31 L23.5 25.5 L34 30.5" fill="none" stroke="#ffb454" stroke-width="2.6"
+        stroke-linecap="round" stroke-linejoin="round"/>
+  <circle cx="14" cy="31" r="2.6" fill="#eaf6f4"/>
+  <circle cx="34" cy="30.5" r="2.6" fill="#ffb454"/>
+</svg>
diff --git a/public/site.webmanifest b/public/site.webmanifest
new file mode 100644
index 0000000..3865480
--- /dev/null
+++ b/public/site.webmanifest
@@ -0,0 +1,13 @@
+{
+  "name": "Cave Survey Viewer",
+  "short_name": "CaveViewer",
+  "description": "A web-native 3D viewer for cave survey data. Runs entirely in your browser.",
+  "icons": [
+    { "src": "/android-chrome-192x192.png", "sizes": "192x192", "type": "image/png" },
+    { "src": "/android-chrome-512x512.png", "sizes": "512x512", "type": "image/png" }
+  ],
+  "theme_color": "#121a28",
+  "background_color": "#121a28",
+  "display": "standalone",
+  "start_url": "/"
+}