diff --git a/index.html b/index.html
index 9f3ead64..30ad9312 100644
--- a/index.html
+++ b/index.html
@@ -3,7 +3,9 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta name="theme-color" content="#4F5BFF" />
     <title>또랑</title>
+    <meta name="description" content="가장 쉽고 빠른 발표 피드백, 또랑" />
     <link rel="preconnect" href="https://cdn.jsdelivr.net" crossorigin />
     <link
       rel="stylesheet"
@@ -12,9 +14,22 @@
     <link rel="manifest" href="site.webmanifest" />
     <link rel="apple-touch-icon" sizes="180x180" href="apple-touch-icon.png" />
     <meta name="apple-mobile-web-app-title" content="또랑" />
+    <meta property="og:type" content="website" />
+    <meta property="og:title" content="또랑" />
+    <meta property="og:description" content="가장 쉽고 빠른 발표 피드백, 또랑" />
+    <meta property="og:image" content="/og-image.png" />
+    <meta property="og:locale" content="ko_KR" />
+    <meta name="twitter:card" content="summary_large_image" />
+    <meta name="twitter:title" content="또랑" />
+    <meta name="twitter:description" content="가장 쉽고 빠른 발표 피드백, 또랑" />
+    <meta name="twitter:image" content="/og-image.png" />
     <link rel="icon" type="image/svg+xml" href="favicon.svg" />
     <link rel="icon" type="image/png" href="favicon-96x96.png" sizes="96x96" />
     <link rel="shortcut icon" href="favicon.ico" />
+    <script>
+        !function(t,e){var o,n,p,r;e.__SV||(window.posthog=e,e._i=[],e.init=function(i,s,a){function g(t,e){var o=e.split(".");2==o.length&&(t=t[o[0]],e=o[1]),t[e]=function(){t.push([e].concat(Array.prototype.slice.call(arguments,0)))}}(p=t.createElement("script")).type="text/javascript",p.crossOrigin="anonymous",p.async=!0,p.src=s.api_host.replace(".i.posthog.com","-assets.i.posthog.com")+"/static/array.js",(r=t.getElementsByTagName("script")[0]).parentNode.insertBefore(p,r);var u=e;for(void 0!==a?u=e[a]=[]:a="posthog",u.people=u.people||[],u.toString=function(t){var e="posthog";return"posthog"!==a&&(e+="."+a),t||(e+=" (stub)"),e},u.people.toString=function(){return u.toString(1)+".people (stub)"},o="init capture register register_once register_for_session unregister unregister_for_session getFeatureFlag getFeatureFlagPayload isFeatureEnabled reloadFeatureFlags updateEarlyAccessFeatureEnrollment getEarlyAccessFeatures on onFeatureFlags onSessionId getSurveys getActiveMatchingSurveys renderSurvey canRenderSurvey getNextSurveyStep identify setPersonProperties group resetGroups setPersonPropertiesForFlags resetPersonPropertiesForFlags setGroupPropertiesForFlags resetGroupPropertiesForFlags reset get_distinct_id getGroups get_session_id get_session_replay_url alias set_config startSessionRecording stopSessionRecording sessionRecordingStarted captureException loadToolbar get_property getSessionProperty createPersonProfile opt_in_capturing opt_out_capturing has_opted_in_capturing has_opted_out_capturing clear_opt_in_out_capturing debug".split(" "),n=0;n<o.length;n++)g(u,o[n]);e._i.push([i,s,a])},e.__SV=1)}(document,window.posthog||[]);
+        posthog.init('phc_gOM0XCnEFz0tHv6ZacyEbqkhRCfl1n23mMMXx4zQUYT',{api_host:'https://us.i.posthog.com', defaults:'2026-01-30'})
+    </script>
   </head>
   <body>
     <div id="root"></div>
diff --git a/public/apple-touch-icon.png b/public/apple-touch-icon.png
index ff0618d7..d5d37979 100644
Binary files a/public/apple-touch-icon.png and b/public/apple-touch-icon.png differ
diff --git a/public/favicon-96x96.png b/public/favicon-96x96.png
index 5e063bb1..cb6872b1 100644
Binary files a/public/favicon-96x96.png and b/public/favicon-96x96.png differ
diff --git a/public/favicon.ico b/public/favicon.ico
index 781a1289..195f6dbb 100644
Binary files a/public/favicon.ico and b/public/favicon.ico differ
diff --git a/public/favicon.svg b/public/favicon.svg
index f89f2066..350baf45 100644
--- a/public/favicon.svg
+++ b/public/favicon.svg
@@ -1,13 +1,4 @@
-<svg xmlns="http://www.w3.org/2000/svg" version="1.1" xmlns:xlink="http://www.w3.org/1999/xlink" width="512" height="512"><svg xmlns="http://www.w3.org/2000/svg" version="1.1" xmlns:xlink="http://www.w3.org/1999/xlink" width="512" height="512"><svg width="512" height="512" viewBox="0 0 512 512" fill="none" xmlns="http://www.w3.org/2000/svg">
-<g clip-path="url(#clip0_2371_14301)">
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-<path d="M397.774 87.9284C460.859 105.535 497.727 170.948 480.121 234.034C479.958 234.619 479.788 235.201 479.616 235.781C456.099 317.17 399.331 380.1 328.245 413.907C324.108 415.874 320.683 410.195 324.005 407.041C344.446 387.629 361.78 364.605 374.901 338.592C379.085 330.298 371.901 320.991 362.616 320.727C353.145 320.459 343.554 319.043 334.016 316.381C270.93 298.774 234.062 233.361 251.669 170.275C269.275 107.19 334.689 70.322 397.774 87.9284Z" fill="#4F5BFF"></path>
-</g>
-<defs>
-<clipPath id="clip0_2371_14301">
-<rect width="512" height="512" fill="white"></rect>
-</clipPath>
-</defs>
-</svg></svg><style>@media (prefers-color-scheme: light) { :root { filter: none; } }
-@media (prefers-color-scheme: dark) { :root { filter: none; } }
-</style></svg>
+<svg width="512" height="512" viewBox="0 0 512 512" fill="none" xmlns="http://www.w3.org/2000/svg">
+<path d="M206.545 133.491C256.655 147.476 285.94 199.436 271.955 249.545C271.825 250.01 271.69 250.472 271.554 250.933C255.447 306.675 219.706 351.517 173.968 380.028C167.049 384.341 160.34 374.347 165.474 368.012C169.972 362.461 174.19 356.641 178.099 350.569C187.048 336.668 174.174 319.61 158.147 315.553C157.398 315.363 156.649 315.164 155.901 314.955C105.791 300.97 76.5062 249.011 90.4913 198.901C104.476 148.791 156.436 119.506 206.545 133.491Z" fill="#5E82F7"/>
+<path d="M356.468 133.491C406.578 147.476 435.863 199.436 421.878 249.545C421.748 250.01 421.613 250.472 421.477 250.933C405.37 306.675 369.628 351.517 323.891 380.028C316.971 384.341 310.263 374.347 315.396 368.012C319.895 362.461 324.113 356.641 328.022 350.569C336.97 336.668 324.096 319.61 308.07 315.553C307.321 315.363 306.572 315.164 305.824 314.955C255.714 300.97 226.429 249.011 240.414 198.901C254.399 148.791 306.358 119.506 356.468 133.491Z" fill="#4F5BFF"/>
+</svg>
diff --git a/public/og-image.png b/public/og-image.png
new file mode 100644
index 00000000..8d9820cc
Binary files /dev/null and b/public/og-image.png differ
diff --git a/public/robots.txt b/public/robots.txt
new file mode 100644
index 00000000..23654558
--- /dev/null
+++ b/public/robots.txt
@@ -0,0 +1,8 @@
+User-agent: *
+Allow: /
+Disallow: /dev
+Disallow: /auth/callback
+
+Sitemap: https://ttorang.com/sitemap.xml
+
+#DaumWebMasterTool:a156121360345cf19b1246a7aff4562c93dcb6cd0fc0273cc6a6f74351424ca6:epG3XsgQs63qHOAcJoVUhQ==
diff --git a/public/site.webmanifest b/public/site.webmanifest
index b75446f3..a4237e05 100644
--- a/public/site.webmanifest
+++ b/public/site.webmanifest
@@ -6,16 +6,28 @@
       "src": "/web-app-manifest-192x192.png",
       "sizes": "192x192",
       "type": "image/png",
-      "purpose": "maskable"
+      "purpose": "any"
     },
     {
       "src": "/web-app-manifest-512x512.png",
       "sizes": "512x512",
       "type": "image/png",
+      "purpose": "any"
+    },
+    {
+      "src": "/web-app-manifest-192x192-maskable.png",
+      "sizes": "192x192",
+      "type": "image/png",
+      "purpose": "maskable"
+    },
+    {
+      "src": "/web-app-manifest-512x512-maskable.png",
+      "sizes": "512x512",
+      "type": "image/png",
       "purpose": "maskable"
     }
   ],
-  "theme_color": "#ffffff",
-  "background_color": "#ffffff",
+  "theme_color": "#4F5BFF",
+  "background_color": "#F8FAFF",
   "display": "standalone"
-}
\ No newline at end of file
+}
diff --git a/public/sitemap.xml b/public/sitemap.xml
new file mode 100644
index 00000000..8c5d4274
--- /dev/null
+++ b/public/sitemap.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
+  <url>
+    <loc>https://ttorang.com/</loc>
+    <changefreq>daily</changefreq>
+    <priority>1.0</priority>
+  </url>
+</urlset>
diff --git a/public/web-app-manifest-192x192-maskable.png b/public/web-app-manifest-192x192-maskable.png
new file mode 100644
index 00000000..0d2524ad
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diff --git a/public/web-app-manifest-192x192.png b/public/web-app-manifest-192x192.png
index 797fa9ed..f9bb7cfa 100644
Binary files a/public/web-app-manifest-192x192.png and b/public/web-app-manifest-192x192.png differ
diff --git a/public/web-app-manifest-512x512-maskable.png b/public/web-app-manifest-512x512-maskable.png
new file mode 100644
index 00000000..a2a24f0b
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diff --git a/public/web-app-manifest-512x512.png b/public/web-app-manifest-512x512.png
index 31d60308..82bc3ea3 100644
Binary files a/public/web-app-manifest-512x512.png and b/public/web-app-manifest-512x512.png differ
