diff --git a/Gemfile b/Gemfile
index 08108e8..ec48180 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,7 @@
 source 'https://rubygems.org'
 
 gem 'github-pages'
+gem 'jekyll-seo-tag'
 
 group :scripts do 
   gem 'mgem' 
diff --git a/Gemfile.lock b/Gemfile.lock
index 3fc6b66..ce9db40 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -266,6 +266,7 @@ PLATFORMS
 DEPENDENCIES
   git
   github-pages
+  jekyll-seo-tag
   mgem
   yard-coderay
   yard-mruby
diff --git a/_config.yml b/_config.yml
index 8210404..739cd95 100644
--- a/_config.yml
+++ b/_config.yml
@@ -10,7 +10,13 @@ markdown: kramdown
 highlighter: rouge
 url: https://mruby.org
 repository: https://github.com/mruby/mruby.github.io
-include: _index.html
+include: ['_index.html']
+image:
+  path: /images/mruby_logo_red_icon.png
+  height: 300
+  width: 300
+plugins:
+  - jekyll-seo-tag
 exclude:
 - Gemfile
 - Gemfile.lock
diff --git a/_includes/header.html b/_includes/header.html
index 99526ce..e36a716 100644
--- a/_includes/header.html
+++ b/_includes/header.html
@@ -1,9 +1,7 @@
         <meta charset="utf-8">
-
+        <meta name="viewport" content="width=device-width,initial-scale=1">
         <title>{{ page.title }}</title>
 
-        {% include icons.html %}
-
         <!-- Bootstrap CSS -->
         <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@4.5.3/dist/css/bootstrap.min.css" integrity="sha384-TX8t27EcRE3e/ihU7zmQxVncDAy5uIKz4rEkgIXeMed4M0jlfIDPvg6uqKI2xXr2" crossorigin="anonymous">
 
@@ -16,3 +14,6 @@
 
         <!-- Custom CSS -->
         <link rel="stylesheet" href="/css/main.css">
+
+        {% include icons.html %}
+        {% seo title=false %}
diff --git a/_includes/icons.html b/_includes/icons.html
index a3ac776..96f6a83 100644
--- a/_includes/icons.html
+++ b/_includes/icons.html
@@ -1,8 +1,20 @@
+<!-- Favicon -->
+<link rel="apple-touch-icon" sizes="57x57" href="/images/icons/apple-touch-icon-57x57.png?v=1">
+<link rel="apple-touch-icon" sizes="60x60" href="/images/icons/apple-touch-icon-60x60.png?v=1">
+<link rel="apple-touch-icon" sizes="72x72" href="/images/icons/apple-touch-icon-72x72.png?v=1">
+<link rel="apple-touch-icon" sizes="76x76" href="/images/icons/apple-touch-icon-76x76.png?v=1">
+<link rel="apple-touch-icon" sizes="114x114" href="/images/icons/apple-touch-icon-114x114.png?v=1">
+<link rel="apple-touch-icon" sizes="120x120" href="/images/icons/apple-touch-icon-120x120.png?v=1">
+<link rel="apple-touch-icon" sizes="144x144" href="/images/icons/apple-touch-icon-144x144.png?v=1">
+<link rel="apple-touch-icon" sizes="152x152" href="/images/icons/apple-touch-icon-152x152.png?v=1">
+<link rel="apple-touch-icon" sizes="180x180" href="/images/icons/apple-touch-icon-180x180.png?v=1">
+<link rel="icon" type="image/png" sizes="32x32" href="/images/icons/favicon-32x32.png?v=1">
+<link rel="icon" type="image/png" sizes="192x192" href="/images/icons/android-chrome-192x192.png?v=1">
+<link rel="icon" type="image/png" sizes="16x16" href="/images/icons/favicon-16x16.png?v=1">
+<link rel="manifest" href="/images/icons/site.webmanifest?v=1">
+<link rel="mask-icon" href="/images/icons/safari-pinned-tab.svg?v=1" color="#e0115f">
+<link rel="shortcut icon" href="/favicon.ico?v=1">
+<meta name="msapplication-TileColor" content="#da532c">
+<meta name="msapplication-TileImage" content="/images/icons/mstile-144x144.png?v=1">
+<meta name="msapplication-config" content="/images/icons/browserconfig.xml?v=1">
 <meta name="theme-color" content="#e0115f">
-
-        <!-- Favicon -->
-        <link rel="icon" type="image/x-icon" href="/favicon.ico">
-        <link rel="apple-touch-icon" sizes="180x180" href="/images/icons/apple-touch-icon.png">
-        <link rel="icon" type="image/png" sizes="32x32" href="/images/icons/favicon-32x32.png">
-        <link rel="icon" type="image/png" sizes="16x16" href="/images/icons/favicon-16x16.png">
-        <link rel="manifest" href="/images/icons/site.webmanifest">
diff --git a/_includes/navigation.html b/_includes/navigation.html
index 2258e71..342c05d 100644
--- a/_includes/navigation.html
+++ b/_includes/navigation.html
@@ -1,6 +1,8 @@
             <nav class="navbar navbar-mruby" role="navigation">
               <div class="navbar-header">
-                <a href="/"><img src="/images/mruby_header.png" alt="mruby" title="mruby"></a>
+                <a href="/">
+                  <img src="/images/mruby_header.png" alt="mruby" title="mruby" width="214" height="90">
+                </a>
               </div>
 
               <div>
@@ -30,5 +32,4 @@
                 </form>
                 -->
               </div>
-
             </nav>
diff --git a/_layouts/default.html b/_layouts/default.html
index 3368f4b..f8b046d 100644
--- a/_layouts/default.html
+++ b/_layouts/default.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html>
+<html lang="en">
   <head>
     {% include header.html %}
   </head>
diff --git a/_layouts/post.html b/_layouts/post.html
index def6ea4..76b6209 100644
--- a/_layouts/post.html
+++ b/_layouts/post.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html>
+<html lang="en">
   <head>
     {% include header.html %}
   </head>
diff --git a/browserconfig.xml b/browserconfig.xml
new file mode 100644
index 0000000..4404d1b
--- /dev/null
+++ b/browserconfig.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<browserconfig><msapplication><tile><square70x70logo src="/images/icons/ms-icon-70x70.png"/><square150x150logo src="/images/icons/ms-icon-150x150.png"/><square310x310logo src="/images/icons/ms-icon-310x310.png"/><TileColor>#e0115f</TileColor></tile></msapplication></browserconfig>
\ No newline at end of file
diff --git a/favicon.ico b/favicon.ico
index 5dff910..b2f984d 100644
Binary files a/favicon.ico and b/favicon.ico differ
diff --git a/images/icons/android-chrome-144x144.png b/images/icons/android-chrome-144x144.png
new file mode 100644
index 0000000..2e198d8
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diff --git a/images/icons/android-chrome-256x256.png b/images/icons/android-chrome-256x256.png
new file mode 100644
index 0000000..5c3b635
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diff --git a/images/icons/android-chrome-36x36.png b/images/icons/android-chrome-36x36.png
new file mode 100644
index 0000000..aa54e04
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diff --git a/images/icons/android-chrome-48x48.png b/images/icons/android-chrome-48x48.png
new file mode 100644
index 0000000..1f5cca9
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diff --git a/images/icons/android-chrome-72x72.png b/images/icons/android-chrome-72x72.png
new file mode 100644
index 0000000..b73d85e
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diff --git a/images/icons/android-chrome-96x96.png b/images/icons/android-chrome-96x96.png
new file mode 100644
index 0000000..1b08615
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diff --git a/images/icons/apple-touch-icon-114x114.png b/images/icons/apple-touch-icon-114x114.png
new file mode 100644
index 0000000..ac190ae
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diff --git a/images/icons/apple-touch-icon-120x120.png b/images/icons/apple-touch-icon-120x120.png
new file mode 100644
index 0000000..76c4e8a
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diff --git a/images/icons/apple-touch-icon-144x144.png b/images/icons/apple-touch-icon-144x144.png
new file mode 100644
index 0000000..ecb374c
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diff --git a/images/icons/apple-touch-icon-152x152.png b/images/icons/apple-touch-icon-152x152.png
new file mode 100644
index 0000000..d41363f
Binary files /dev/null and b/images/icons/apple-touch-icon-152x152.png differ
diff --git a/images/icons/apple-touch-icon-180x180.png b/images/icons/apple-touch-icon-180x180.png
new file mode 100644
index 0000000..df878d1
Binary files /dev/null and b/images/icons/apple-touch-icon-180x180.png differ
diff --git a/images/icons/apple-touch-icon-57x57.png b/images/icons/apple-touch-icon-57x57.png
new file mode 100644
index 0000000..51641d9
Binary files /dev/null and b/images/icons/apple-touch-icon-57x57.png differ
diff --git a/images/icons/apple-touch-icon-60x60.png b/images/icons/apple-touch-icon-60x60.png
new file mode 100644
index 0000000..a58443d
Binary files /dev/null and b/images/icons/apple-touch-icon-60x60.png differ
diff --git a/images/icons/apple-touch-icon-72x72.png b/images/icons/apple-touch-icon-72x72.png
new file mode 100644
index 0000000..5649320
Binary files /dev/null and b/images/icons/apple-touch-icon-72x72.png differ
diff --git a/images/icons/apple-touch-icon-76x76.png b/images/icons/apple-touch-icon-76x76.png
new file mode 100644
index 0000000..9e09a88
Binary files /dev/null and b/images/icons/apple-touch-icon-76x76.png differ
diff --git a/images/icons/apple-touch-icon.png b/images/icons/apple-touch-icon.png
index a0fa9ba..51641d9 100644
Binary files a/images/icons/apple-touch-icon.png and b/images/icons/apple-touch-icon.png differ
diff --git a/images/icons/favicon-16x16.png b/images/icons/favicon-16x16.png
index 1311dd4..19dfffc 100644
Binary files a/images/icons/favicon-16x16.png and b/images/icons/favicon-16x16.png differ
diff --git a/images/icons/favicon-32x32.png b/images/icons/favicon-32x32.png
index 2cc3b44..16677cf 100644
Binary files a/images/icons/favicon-32x32.png and b/images/icons/favicon-32x32.png differ
diff --git a/images/icons/favicon-96x96.png b/images/icons/favicon-96x96.png
new file mode 100644
index 0000000..64b667a
Binary files /dev/null and b/images/icons/favicon-96x96.png differ
diff --git a/images/icons/maskable_icon.png b/images/icons/maskable_icon.png
new file mode 100644
index 0000000..175d9df
Binary files /dev/null and b/images/icons/maskable_icon.png differ
diff --git a/images/icons/ms-icon-144x144.png b/images/icons/ms-icon-144x144.png
new file mode 100644
index 0000000..73b2340
Binary files /dev/null and b/images/icons/ms-icon-144x144.png differ
diff --git a/images/icons/ms-icon-150x150.png b/images/icons/ms-icon-150x150.png
new file mode 100644
index 0000000..2684b0c
Binary files /dev/null and b/images/icons/ms-icon-150x150.png differ
diff --git a/images/icons/ms-icon-310x310.png b/images/icons/ms-icon-310x310.png
new file mode 100644
index 0000000..ba24e58
Binary files /dev/null and b/images/icons/ms-icon-310x310.png differ
diff --git a/images/icons/ms-icon-70x70.png b/images/icons/ms-icon-70x70.png
new file mode 100644
index 0000000..c48fc8d
Binary files /dev/null and b/images/icons/ms-icon-70x70.png differ
diff --git a/images/icons/safari-pinned-tab.svg b/images/icons/safari-pinned-tab.svg
new file mode 100644
index 0000000..9ee086b
--- /dev/null
+++ b/images/icons/safari-pinned-tab.svg
@@ -0,0 +1 @@
+<svg version="1" xmlns="http://www.w3.org/2000/svg" width="400" height="400" viewBox="0 0 300.000000 300.000000"><path d="M159.5 21.8c-2.8 1-6.6 2.8-8.4 4.1-4.7 3.4-44.1 10.9-51.6 10-7.8-1.1-18.1.7-24.4 4.2-4 2.1-9.4 3.8-18.6 5.5-14.3 2.8-19.3 5.2-22.1 10.5-1.5 2.9-1.4 7.5 1.5 65.3 1.8 34.1 3.4 63.4 3.6 65.1.8 5 45 86.6 48.9 90.2 3.6 3.4 8.9 5.3 14.5 5.3 5.5 0 146.1-33.9 150.2-36.2 7-3.9 6.7-2.3 11-64.1 2.1-30.9 3.9-59.1 3.9-62.6v-6.4l-27.6-42.1c-15.2-23.2-29.2-43.5-31.1-45.2-4.6-4.3-9.1-5.1-28.3-5.2-13.2-.1-17.5.2-21.5 1.6zm27.2 8.2c17.4 7.7 8.9 23.3-12.7 23.4-4.9.1-9.1-.6-12.2-1.7-5.4-2.1-10.8-7.7-10.8-11.2 0-2.6 4-7.9 7.4-9.7 7.3-4 20.3-4.3 28.3-.8zm17.1.7c1.9 1.7 55.7 82.9 56.8 85.8.3.7-.5 2.5-1.8 4-2.3 2.6-5.2 3.3-77.4 17.7-80.8 16.1-83.3 16.4-87.9 11.7-1.3-1.3-13.7-21.5-27.5-44.7-19.4-32.6-25-42.9-24.6-44.7.7-2.9 5.2-5 14.9-6.7l7.7-1.5v11.4c0 12.7.8 15.1 6.4 20 4.1 3.7 13.2 7.3 18.3 7.3 3.2 0 3.5.2 2.7 2.2-.4 1.3-.9 7.8-1.1 14.5-.4 10.8-.2 12.6 1.7 16.2 4.3 8.6 15.1 13.5 29.5 13.5 10.6 0 15.5-1.2 22.2-5.7 7.5-5 9.3-9.5 9.3-23.5 0-9.4-.3-12-2-15.3-3.5-6.8-12.1-11.5-24.3-13.4-3.2-.5-3.7-.9-3.1-2.3.5-.9 1-6.7 1.2-12.9.3-11.8-.5-15-5-20l-2-2.1 5.4-1.1c2.9-.6 8.5-1.7 12.5-2.4l7.1-1.4.4 11.3c.3 10.6.5 11.5 3.3 15.6 3.8 5.2 11.8 9.6 19.8 10.7 3.1.4 5.9 1 6.2 1.3.3.3-.2 2.2-1.1 4.4-2.5 6-1.7 24.6 1.4 29.5 8.9 14.4 38.9 17.4 53.1 5.3 6.1-5.3 7.1-8.3 7.1-21.6 0-9.3-.3-11.9-2.1-15.5-3.6-7.4-14.7-13.3-25.1-13.3-4.8 0-5-.1-4.3-2.3.5-1.2 1-7.5 1.2-14 .4-10.2.2-12.3-1.5-15.7-2.1-4.4-1-5.4 2.6-2.3zm-96.3 15.2c9 4.1 11.6 11.3 6 17.1C102.8 74.2 72 69.6 72 56.8c0-3.8 1.3-6.2 4.9-8.7 7.2-5.1 21.7-6.2 30.6-2.2zm108.6 29.2c8.8 3.8 11.9 10.3 8.1 16.5-4.7 7.4-22.7 10.8-34.4 6.4-6.2-2.3-11.8-7.6-11.8-11.3 0-5.8 7.1-11.8 16.3-13.7 6-1.3 16.2-.3 21.8 2.1zm-79.2 15.6c7.1 3.5 10.1 8.5 8 13.5-5.1 12.4-33.9 14.5-44.4 3.2-6.2-6.7-.3-16.2 12.2-19.4 6.8-1.7 17.9-.5 24.2 2.7zm70.8 74.9c5.8 4.3 5.8 4.9 3.6 36.7-1.2 15.8-2.3 29-2.5 29.3-.3.2-12.8 1.3-28 2.4-29.5 2.1-32.7 1.9-36.7-2.4-3.2-3.4-3.8-7.4-3.1-21.6.4-10.3.9-13.3 2.8-17.2 2.8-5.6 14.6-18.6 21-23 8.6-5.9 12.3-6.8 26.9-6.5 11.6.2 13.5.5 16 2.3z"/><path d="M187.7 178.3c-1.5 4.6-2.7 8.6-2.7 8.9 0 .6 21.7-.1 23.8-.8 1.1-.3-9.1-9.4-17.4-15.5-.6-.5-2 2.1-3.7 7.4zM174.3 198.1c-5.1 4.9-9.3 9.2-9.3 9.4 0 .7 25.3 8.6 25.8 8.1.5-.6-6.1-26.6-6.8-26.6-.3 0-4.7 4.1-9.7 9.1zM154.2 210c-4 .9-7.5 2-7.8 2.2-.2.3 1.2 4.3 3.2 8.9 2 4.6 4 9.5 4.5 10.8.5 1.3 1.2 2.2 1.4 1.9.6-.6 7.5-23.3 7.5-24.7 0-1.3.4-1.3-8.8.9z"/></svg>
\ No newline at end of file
diff --git a/images/icons/site.webmanifest b/images/icons/site.webmanifest
index 71544e3..a13235d 100644
--- a/images/icons/site.webmanifest
+++ b/images/icons/site.webmanifest
@@ -2,12 +2,57 @@
   "name":"mruby Lightweight Ruby",
   "short_name":"mruby",
   "icons":[
-    {"src":"/images/icons/android-chrome-192x192.png","sizes":"192x192","type":"image/png"},
-    {"src":"/images/icons/android-chrome-512x512.png","sizes":"512x512","type":"image/png"}],
+    {
+        "src": "/images/icons/android-chrome-36x36.png?v=1",
+        "sizes": "36x36",
+        "type": "image/png"
+    },
+    {
+        "src": "/images/icons/android-chrome-48x48.png?v=1",
+        "sizes": "48x48",
+        "type": "image/png"
+    },
+    {
+        "src": "/images/icons/android-chrome-72x72.png?v=1",
+        "sizes": "72x72",
+        "type": "image/png"
+    },
+    {
+        "src": "/images/icons/android-chrome-96x96.png?v=1",
+        "sizes": "96x96",
+        "type": "image/png"
+    },
+    {
+        "src": "/images/icons/android-chrome-144x144.png?v=1",
+        "sizes": "144x144",
+        "type": "image/png"
+    },
+    {
+      "src":"/images/icons/android-chrome-192x192.png?v=1",
+      "sizes":"192x192",
+      "type":"image/png"
+    },
+    {
+      "src": "/images/icons/android-chrome-256x256.png?v=1",
+      "sizes": "256x256",
+      "type": "image/png"
+    },
+    {
+      "src":"/images/icons/android-chrome-512x512.png?v=1",
+      "sizes":"512x512",
+      "type":"image/png"
+    },
+    {
+      "src": "/images/icons/maskable_icon.png?v=1",
+      "sizes": "196x196",
+      "type": "image/png",
+      "purpose": "any maskable"
+    }],
   "theme_color":"#e0115f",
   "background_color":"#ffffff",
   "display":"standalone",
   "start_url": "/?source=pwa",
   "scope": "/",
-  "orientation":"portrait"
+  "orientation":"portrait",
+  "lang":"en"
 }
diff --git a/index.html b/index.html
index 79720ee..960fa8c 100644
--- a/index.html
+++ b/index.html
@@ -5,7 +5,7 @@
 
 <div class="row clearfix">
   <div class="col-md-12 column mruby-is">
-    <img src="/images/mruby_logo_red_icon.png"/>
+    <img src="/images/mruby_logo_red_icon.png" alt="mruby" title="mruby" width="300" height="300">
     <p>
     mruby is the lightweight implementation of the <a href="https://www.ruby-lang.org">Ruby language</a> complying with part of the <a href="http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=59579">ISO standard</a>. mruby can be linked and embedded within your application.
     </p>
diff --git a/robots.txt b/robots.txt
new file mode 100644
index 0000000..12c4d54
--- /dev/null
+++ b/robots.txt
@@ -0,0 +1 @@
+User-agent: * Disallow: