diff --git a/innovedus_cms/base/static/css/newsletter.css b/innovedus_cms/base/static/css/newsletter.css
index 111fe39..30e9138 100644
--- a/innovedus_cms/base/static/css/newsletter.css
+++ b/innovedus_cms/base/static/css/newsletter.css
@@ -1,5 +1,5 @@
 .newsletter-page {
-  background: #0e1b42 url("../img/newsletter_bg.png") center center / cover no-repeat fixed;
+  background: #0e1b42 url("../img/newsletter_bg.webp") center center / cover no-repeat fixed;
 }
 
 .newsletter-page .site-main > .site-container {
@@ -170,4 +170,4 @@
   .newsletter-back-link__text {
     font-size: 14px;
   }
-}
\ No newline at end of file
+}
diff --git a/innovedus_cms/base/static/img/email/facebook-white.original.png b/innovedus_cms/base/static/img/email/facebook-white.original.png
new file mode 100644
index 0000000..6d87840
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diff --git a/innovedus_cms/base/static/img/email/instagram-white.original.png b/innovedus_cms/base/static/img/email/instagram-white.original.png
new file mode 100644
index 0000000..f3b31e0
Binary files /dev/null and b/innovedus_cms/base/static/img/email/instagram-white.original.png differ
diff --git a/innovedus_cms/base/static/img/email/logo.png b/innovedus_cms/base/static/img/email/logo.png
new file mode 100644
index 0000000..ca652d8
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diff --git a/innovedus_cms/base/static/img/email/mailback.jpg b/innovedus_cms/base/static/img/email/mailback.jpg
new file mode 100644
index 0000000..77922fb
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diff --git a/innovedus_cms/base/static/img/email/threads-white.original.png b/innovedus_cms/base/static/img/email/threads-white.original.png
new file mode 100644
index 0000000..f016f42
Binary files /dev/null and b/innovedus_cms/base/static/img/email/threads-white.original.png differ
diff --git a/innovedus_cms/base/static/img/newsletter_bg.webp b/innovedus_cms/base/static/img/newsletter_bg.webp
new file mode 100644
index 0000000..3451143
Binary files /dev/null and b/innovedus_cms/base/static/img/newsletter_bg.webp differ
diff --git a/innovedus_cms/base/static/img/og_default.jpg b/innovedus_cms/base/static/img/og_default.jpg
new file mode 100644
index 0000000..5e7a69d
Binary files /dev/null and b/innovedus_cms/base/static/img/og_default.jpg differ
diff --git a/innovedus_cms/home/feeds.py b/innovedus_cms/home/feeds.py
index ff473c0..f89b083 100644
--- a/innovedus_cms/home/feeds.py
+++ b/innovedus_cms/home/feeds.py
@@ -1,3 +1,5 @@
+import os
+
 from django.contrib.syndication.views import Feed
 from django.utils.feedgenerator import Rss201rev2Feed
 from django.utils.html import strip_tags
@@ -5,6 +7,20 @@ from django.utils.html import strip_tags
 from .models import ArticlePage
 
 
+def _get_env_int(name, default):
+    value = os.environ.get(name)
+    if value is None:
+        return default
+    try:
+        parsed = int(value)
+    except ValueError:
+        return default
+    return parsed if parsed > 0 else default
+
+
+ARTICLE_FEED_SIZE = _get_env_int("ARTICLE_FEED_SIZE", 50)
+
+
 class LatestArticlesFeed(Feed):
     feed_type = Rss201rev2Feed
     title = "DeBuT AI 最新文章"
@@ -12,7 +28,7 @@ class LatestArticlesFeed(Feed):
     description = "DeBuT AI 最新文章 RSS feed"
 
     def items(self):
-        return ArticlePage.objects.live().order_by("-date", "-id")[:20]
+        return ArticlePage.objects.live().order_by("-date", "-id")[:ARTICLE_FEED_SIZE]
 
     def item_title(self, item):
         return item.title
diff --git a/innovedus_cms/home/static/css/article_list.css b/innovedus_cms/home/static/css/article_list.css
index 4fb498d..22f357f 100644
--- a/innovedus_cms/home/static/css/article_list.css
+++ b/innovedus_cms/home/static/css/article_list.css
@@ -141,23 +141,27 @@
   justify-content: center;
   align-items: center;
   gap: 8px;
-  margin: 40px 0 20px;
-  font-size: 14px;
+  margin: 0;
+  font-size: 12px;
+  font-weight: 400;
+  line-height: 15px;
+  letter-spacing: 0.3em;
 }
 
 .page-size-label {
-  color: #0e1b4266;
+  color: #0e1b42;
 }
 
 .page-size-option {
   display: inline-flex;
   align-items: center;
   justify-content: center;
-  min-width: 40px;
-  height: 32px;
+  min-width: 37px;
+  height: 24px;
   border: 1px solid #0e1b42;
-  border-radius: 4px;
   color: #0e1b42;
+  font-weight: 600;
+  letter-spacing: 0.05em;
 }
 
 .page-size-option.is-current {
diff --git a/innovedus_cms/home/static/css/category.css b/innovedus_cms/home/static/css/category.css
index 222243b..7f41574 100644
--- a/innovedus_cms/home/static/css/category.css
+++ b/innovedus_cms/home/static/css/category.css
@@ -11,6 +11,21 @@
   line-height: 60px;
 } 
 
+.category-toolbar {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 24px;
+}
+
+.category-toolbar .category-title {
+  flex: 0 0 auto;
+}
+
+.category-toolbar .page-size-selector {
+  margin: 0 0 0 auto;
+}
+
 .subcategory-title {
   display: flex;
   align-items: center;
@@ -38,6 +53,16 @@
 }
 
 @media (max-width: 767px) {
+  .category-toolbar {
+    align-items: flex-start;
+    flex-direction: column;
+    gap: 12px;
+  }
+
+  .category-toolbar .page-size-selector {
+    margin-left: 0;
+  }
+
   .subcategory-title::after {
     display: none;
   }
diff --git a/innovedus_cms/home/static/img/default_cover_1.jpg b/innovedus_cms/home/static/img/default_cover_1.jpg
new file mode 100644
index 0000000..f4340dd
Binary files /dev/null and b/innovedus_cms/home/static/img/default_cover_1.jpg differ
diff --git a/innovedus_cms/home/static/img/default_cover_1.png b/innovedus_cms/home/static/img/default_cover_1.png
deleted file mode 100644
index d039c62..0000000
Binary files a/innovedus_cms/home/static/img/default_cover_1.png and /dev/null differ
diff --git a/innovedus_cms/home/static/img/default_cover_2.jpg b/innovedus_cms/home/static/img/default_cover_2.jpg
new file mode 100644
index 0000000..a2772f1
Binary files /dev/null and b/innovedus_cms/home/static/img/default_cover_2.jpg differ
diff --git a/innovedus_cms/home/static/img/default_cover_2.png b/innovedus_cms/home/static/img/default_cover_2.png
deleted file mode 100644
index 1e8436b..0000000
Binary files a/innovedus_cms/home/static/img/default_cover_2.png and /dev/null differ
diff --git a/innovedus_cms/home/static/img/default_cover_3.jpg b/innovedus_cms/home/static/img/default_cover_3.jpg
new file mode 100644
index 0000000..f9ff3f8
Binary files /dev/null and b/innovedus_cms/home/static/img/default_cover_3.jpg differ
diff --git a/innovedus_cms/home/static/img/default_cover_3.png b/innovedus_cms/home/static/img/default_cover_3.png
deleted file mode 100644
index 83e3e27..0000000
Binary files a/innovedus_cms/home/static/img/default_cover_3.png and /dev/null differ
diff --git a/innovedus_cms/home/templates/home/category_page.html b/innovedus_cms/home/templates/home/category_page.html
index cb35545..6d0be30 100644
--- a/innovedus_cms/home/templates/home/category_page.html
+++ b/innovedus_cms/home/templates/home/category_page.html
@@ -27,8 +27,11 @@
     </nav>
   {% endif %}
   <div class="site-hero-band full-bleed">
-    <div class="site-container">
+    <div class="site-container category-toolbar">
       <div class="block-title category-title"><span>{{ self.title}}</span></div>
+      {% if not page.has_subcategories %}
+        {% include "home/includes/page_size_selector.html" with category=category_sections.0 %}
+      {% endif %}
     </div>
   </div>
   {% if page.has_subcategories %}
diff --git a/innovedus_cms/home/templates/home/hashtag_page.html b/innovedus_cms/home/templates/home/hashtag_page.html
index 6acc84f..6874f0a 100644
--- a/innovedus_cms/home/templates/home/hashtag_page.html
+++ b/innovedus_cms/home/templates/home/hashtag_page.html
@@ -5,8 +5,9 @@
 {% endblock %}
 {% block content %}
   <div class="site-hero-band full-bleed">
-    <div class="site-container">
+    <div class="site-container category-toolbar">
       <div class="block-title category-title"><span>#{{ tag.name }}</span></div>
+      {% include "home/includes/page_size_selector.html" with category=category_sections.0 %}
     </div>
   </div>
 
diff --git a/innovedus_cms/home/templates/home/includes/page-article-list.html b/innovedus_cms/home/templates/home/includes/page-article-list.html
index 0908e66..e208d96 100644
--- a/innovedus_cms/home/templates/home/includes/page-article-list.html
+++ b/innovedus_cms/home/templates/home/includes/page-article-list.html
@@ -6,19 +6,6 @@
 <div class="page-article-list">
   {% include "home/includes/article_list.html" with items=category.items show_hero=show_hero empty_message=empty_message %}
 
-  {% if category.pagination.page_size_options %}
-    <div class="page-size-selector" aria-label="每頁文章數">
-      <span class="page-size-label">每頁</span>
-      {% for option in category.pagination.page_size_options %}
-        {% if option.is_current %}
-          <span class="page-size-option is-current">{{ option.value }}</span>
-        {% else %}
-          <a class="page-size-option" href="{{ option.url }}">{{ option.value }}</a>
-        {% endif %}
-      {% endfor %}
-    </div>
-  {% endif %}
-
   {% if category.items.paginator.num_pages > 1 %}
     <div class="pagination">
       {% if category.items.has_previous %}
diff --git a/innovedus_cms/home/templates/home/includes/page_size_selector.html b/innovedus_cms/home/templates/home/includes/page_size_selector.html
new file mode 100644
index 0000000..85115f6
--- /dev/null
+++ b/innovedus_cms/home/templates/home/includes/page_size_selector.html
@@ -0,0 +1,14 @@
+{% if category.pagination.page_size_options %}
+  <div class="page-size-selector" aria-label="每頁文章數">
+    <span class="page-size-label">每頁顯示</span>
+    {% for option in category.pagination.page_size_options %}
+      {% if option.is_current %}
+        <span class="page-size-option is-current">{{ option.value }}</span>
+      {% else %}
+        <span class="page-size-option">
+          <a href="{{ option.url }}">{{ option.value }}</a>
+        </span>
+      {% endif %}
+    {% endfor %}
+  </div>
+{% endif %}
diff --git a/innovedus_cms/home/templatetags/home_tags.py b/innovedus_cms/home/templatetags/home_tags.py
index 152153a..d347e30 100644
--- a/innovedus_cms/home/templatetags/home_tags.py
+++ b/innovedus_cms/home/templatetags/home_tags.py
@@ -9,8 +9,8 @@ register = template.Library()
 @register.simple_tag
 def random_default_cover():
     choices = (
-        "img/default_cover_1.png",
-        "img/default_cover_2.png",
-        "img/default_cover_3.png",
+        "img/default_cover_1.jpg",
+        "img/default_cover_2.jpg",
+        "img/default_cover_3.jpg",
     )
     return static(random.choice(choices))
diff --git a/innovedus_cms/mysite/context_processors.py b/innovedus_cms/mysite/context_processors.py
index ee31c19..834c896 100644
--- a/innovedus_cms/mysite/context_processors.py
+++ b/innovedus_cms/mysite/context_processors.py
@@ -1,7 +1,19 @@
 from django.conf import settings
+from django.templatetags.static import static
 
 
 def ga4(request):
     return {
         "ga4_measurement_id": getattr(settings, "GA4_MEASUREMENT_ID", ""),
     }
+
+
+def default_og_image(request):
+    return {
+        "default_og_image": {
+            "url": request.build_absolute_uri(static("img/og_default.jpg")),
+            "width": 528,
+            "height": 337,
+            "alt": "DeBuT AI",
+        },
+    }
diff --git a/innovedus_cms/mysite/settings/base.py b/innovedus_cms/mysite/settings/base.py
index 1a781c2..6b8a9db 100644
--- a/innovedus_cms/mysite/settings/base.py
+++ b/innovedus_cms/mysite/settings/base.py
@@ -177,6 +177,7 @@ TEMPLATES = [
                 "wagtail.contrib.settings.context_processors.settings",
                 "home.context_processors.navigation_pages",
                 "mysite.context_processors.ga4",
+                "mysite.context_processors.default_og_image",
             ],
         },
     },
diff --git a/innovedus_cms/mysite/static/css/mysite.css b/innovedus_cms/mysite/static/css/mysite.css
index c29e09c..fe66df6 100644
--- a/innovedus_cms/mysite/static/css/mysite.css
+++ b/innovedus_cms/mysite/static/css/mysite.css
@@ -321,6 +321,21 @@ a {
   color: #0e1b42;
 }
 
+.template-darkbackground .page-size-label {
+  color: #ffffff;
+}
+
+.template-darkbackground .page-size-option {
+  border-color: #ffffffb3;
+  color: #ffffffb3;
+}
+
+.template-darkbackground .page-size-option.is-current {
+  background-color: #ffffffb3;
+  background-clip: padding-box;
+  color: #0e1b42;
+}
+
 .template-darkbackground .site-hero-band .news-title {
   height: 60px;
 }
diff --git a/innovedus_cms/mysite/templates/base.html b/innovedus_cms/mysite/templates/base.html
index 14e1044..605e70e 100644
--- a/innovedus_cms/mysite/templates/base.html
+++ b/innovedus_cms/mysite/templates/base.html
@@ -16,11 +16,12 @@
         {% if page.search_description %}
         <meta name="description" content="{{ page.search_description }}" />
         {% endif %}
-        {% if og_image %}
-        <meta property="og:image" content="{{ og_image.url }}" />
-        <meta property="og:image:width" content="{{ og_image.width }}" />
-        <meta property="og:image:height" content="{{ og_image.height }}" />
-        <meta property="og:image:alt" content="{{ og_image.alt }}" />
+        {% firstof og_image default_og_image as resolved_og_image %}
+        {% if resolved_og_image %}
+        <meta property="og:image" content="{{ resolved_og_image.url }}" />
+        <meta property="og:image:width" content="{{ resolved_og_image.width }}" />
+        <meta property="og:image:height" content="{{ resolved_og_image.height }}" />
+        <meta property="og:image:alt" content="{{ resolved_og_image.alt }}" />
         {% endif %}
         <meta name="viewport" content="width=device-width, initial-scale=1" />
         <link rel="alternate" type="application/rss+xml" title="DeBuT AI 最新文章 RSS" href="{% url 'article_feed' %}">
diff --git a/innovedus_cms/search/templates/search/search.html b/innovedus_cms/search/templates/search/search.html
index 6b84773..b80e54a 100644
--- a/innovedus_cms/search/templates/search/search.html
+++ b/innovedus_cms/search/templates/search/search.html
@@ -14,8 +14,11 @@
 {% block content %}
   {% if search_query %}
     <div class="site-hero-band full-bleed">
-      <div class="site-container">
+      <div class="site-container category-toolbar">
         <div class="block-title category-title"><span>{{ search_query }}</span></div>
+        {% if results_count %}
+          {% include "home/includes/page_size_selector.html" with category=category_sections.0 %}
+        {% endif %}
       </div>
     </div>
   {% endif %}