diff --git a/forum/form.py b/forum/form.py
index 05ff949..001e88d 100644
--- a/forum/form.py
+++ b/forum/form.py
@@ -37,14 +37,14 @@ def __init__(self, *args, user=None, **kwargs):
 
     class Meta:
         model = Collection
-        fields = ['name', 'description']
+        fields = ['name', 'content']
         labels = {
             'name': '合集名称',
-            'description': '描述',
+            'content': '描述',
         }
         widgets = {
             'name': forms.TextInput(attrs={'class': 'form-control'}),
-            'description': forms.Textarea(attrs={'rows': 3, 'class': 'form-control'}),
+            'content': forms.Textarea(attrs={'rows': 3, 'class': 'form-control'}),
         }
 
     def save(self, commit=True):
diff --git a/forum/models.py b/forum/models.py
index 0880d48..d9e5afd 100644
--- a/forum/models.py
+++ b/forum/models.py
@@ -3,9 +3,6 @@
 
 from .markdown import MarkdownModel
 
-import markdown
-import bleach
-
 # Create your models here.
 
 class Item(MarkdownModel):
@@ -47,11 +44,9 @@ def __str__(self):
         return f"{self.author} comment {self.post}"
 
 
-class Collection(models.Model):
+class Collection(MarkdownModel):
     owner = models.ForeignKey(User, on_delete=models.CASCADE, related_name='collections')
     name = models.CharField(max_length=100)
-    description = models.TextField(blank=True, default='')
-    description_html = models.TextField(editable=False, blank=True)
     created_at = models.DateTimeField(auto_now_add=True)
 
     class Meta:
@@ -60,19 +55,6 @@ class Meta:
     def __str__(self):
         return self.name
 
-    def save(self, *args, **kwargs):
-        if self.description:
-            html = markdown.markdown(self.description, extensions=MarkdownModel.MARKDOWN_EXTENSIONS)
-            self.description_html = bleach.clean(
-                html,
-                tags=MarkdownModel.allowed_tags,
-                attributes=MarkdownModel.allowed_attrs,
-                protocols=MarkdownModel.ALLOWED_PROTOCOLS,
-            )
-        else:
-            self.description_html = ''
-        super().save(*args, **kwargs)
-
 
 class CollectionPost(models.Model):
     collection = models.ForeignKey(Collection, on_delete=models.CASCADE, related_name='collection_posts')
diff --git a/forum/templates/base.html b/forum/templates/base.html
index cec2719..76a6596 100644
--- a/forum/templates/base.html
+++ b/forum/templates/base.html
@@ -122,7 +122,7 @@
         function updateThemeIcon() {
             const icon = document.getElementById('theme-icon');
             const isDark = document.documentElement.getAttribute('data-bs-theme') === 'dark';
-            icon.className = 'bi ' + (isDark ? 'bi-sun' : 'bi-moon-stars');
+            icon.className = 'bi ' + (isDark ? 'bi-moon' : 'bi-sun');
         }
         updateThemeIcon();
 
diff --git a/forum/templates/forum/collection_detail.html b/forum/templates/forum/collection_detail.html
index 465b31f..e460b55 100644
--- a/forum/templates/forum/collection_detail.html
+++ b/forum/templates/forum/collection_detail.html
@@ -4,8 +4,8 @@
 
 {% block content %}
 <h1>{{ collection.name }}</h1>
-{% if collection.description_html %}
-<div class="markdown-body mb-3">{{ collection.description_html|safe }}</div>
+{% if collection.content_html %}
+<div class="markdown-body mb-3">{{ collection.content_html|safe }}</div>
 {% endif %}
 
 <p class="text-muted">
diff --git a/forum/templates/forum/collection_form.html b/forum/templates/forum/collection_form.html
index 7a483bb..86118f6 100644
--- a/forum/templates/forum/collection_form.html
+++ b/forum/templates/forum/collection_form.html
@@ -1,9 +1,9 @@
 {% extends 'base.html' %}
 
-{% block title %}{{ title }}{% endblock %}
+{% block title %}创建合集{% endblock %}
 
 {% block content %}
-<h1>{{ title }}</h1>
+<h1>创建合集</h1>
 
 <form method="post" class="mt-3">
     {% csrf_token %}
diff --git a/forum/templates/forum/collection_list.html b/forum/templates/forum/collection_list.html
index 9e9c854..d7d8769 100644
--- a/forum/templates/forum/collection_list.html
+++ b/forum/templates/forum/collection_list.html
@@ -14,8 +14,8 @@ <h1>合集</h1>
     <div>
       <a href="{% url 'collection_detail' collection.id %}">{{ collection.name }}</a>
       <small class="text-muted ms-2">by {{ collection.owner.username }}</small>
-      {% if collection.description %}
-      <br><small class="text-muted">{{ collection.description }}</small>
+      {% if collection.content %}
+      <br><small class="text-muted">{{ collection.content | truncatechars:100}}</small>
       {% endif %}
     </div>
     <span class="badge bg-secondary">{{ collection.collection_posts.count }} 篇</span>
diff --git a/forum/templates/forum/post_list.html b/forum/templates/forum/post_list.html
index 8b0d24b..a5bc6a9 100644
--- a/forum/templates/forum/post_list.html
+++ b/forum/templates/forum/post_list.html
@@ -10,14 +10,14 @@ <h1>所有文章</h1>
   {% if item.type == 'collection' %}
   <li>
     <i class="bi bi-collection"></i>
-    <a href="{% url 'collection_detail' item.obj.id %}">{{ item.obj.name }}</a>
-    — 合集 · {{ item.obj.owner.username }}
-    · {{ item.obj.collection_posts.count }} 篇文章
+    <a href="{% url 'collection_detail' item.id %}">{{ item.name }}</a>
+    — 合集 · {{ item.owner.username }}
+    · {{ item.collection_posts.count }} 篇文章
   </li>
   {% else %}
   <li>
-    {{ item.obj.title }} - 作者：{{ item.obj.author }} <small class="text-muted"><i class="bi bi-eye"></i> {{ item.obj.views }}</small>
-    <a href="{% url 'post_detail' item.obj.id %}">去查看</a>
+    {{ item.title }} - 作者：{{ item.author.username }} <small class="text-muted"><i class="bi bi-eye"></i> {{ item.views }}</small>
+    <a href="{% url 'post_detail' item.id %}">去查看</a>
   </li>
   {% endif %}
 {% empty %}
diff --git a/forum/views.py b/forum/views.py
index 1c08d7b..c67d138 100644
--- a/forum/views.py
+++ b/forum/views.py
@@ -1,5 +1,5 @@
 import json, re, random
-from django.db.models import F
+from django.db.models import F, CharField, Subquery, Value
 from django.db import models as db_models
 from django.http import JsonResponse
 from django.urls import reverse_lazy
@@ -22,30 +22,51 @@
 
 def index(request):
     items = Item.objects.all()
-    posts = Post.objects.all().order_by('-created_at')[:5]
+    posts = Post.objects.all()[:5]
     return render(request, 'forum/index.html', {'items': items, 'posts' : posts})
 
 def post_list(request):
-    # IDs of posts that belong to any collection
-    collected_post_ids = CollectionPost.objects.values_list('post_id', flat=True)
-
     # Standalone posts (not in any collection)
-    standalone_posts = [
-        {'type': 'post', 'obj': p, 'date': p.created_at}
-        for p in Post.objects.exclude(id__in=collected_post_ids)
-    ]
+    standalone_posts = Post.objects.exclude(
+        id__in = CollectionPost.objects.values_list('post_id', flat=True)  # IDs of posts that belong to any collection
+    ).annotate(
+        type=Value('post', output_field=CharField())
+    ).values("type", "id", "created_at").order_by()
 
     # Collections as items
-    collection_items = [
-        {'type': 'collection', 'obj': c, 'date': c.created_at}
-        for c in Collection.objects.all()
-    ]
+    collection_items = Collection.objects.annotate(
+        type=Value('collection', output_field=CharField())
+    ).values("type", "id", "created_at").order_by()
+
+    combined = standalone_posts.union(
+        collection_items,
+        all=True
+    ).order_by('-created_at')
+
+    paginator = Paginator(combined, 20)
+    page_items = paginator.get_page(request.GET.get('page', 1))
+
+    page_post_ids = []
+    page_collection_ids = []
+    for row in page_items:
+        if row["type"] == "post":
+            page_post_ids.append(row["id"])
+        else:
+            page_collection_ids.append(row["id"])
+    
+    posts = Post.objects.in_bulk(page_post_ids)
+    collections = Collection.objects.in_bulk(page_collection_ids)
 
-    # Merge and sort by date descending
-    items = sorted(standalone_posts + collection_items, key=lambda x: x['date'], reverse=True)
 
-    paginator = Paginator(items, 20)
-    page_obj = paginator.get_page(request.GET.get('page', 1))
+    page_obj = []
+    for row in page_items:
+        if row["type"] == "post":
+            obj = posts.get(row["id"])
+        else:
+            obj = collections.get(row["id"])
+        
+        obj.type = row["type"]
+        page_obj.append(obj)
 
     return render(request, 'forum/post_list.html', {
         'page_obj': page_obj,
@@ -254,7 +275,7 @@ def collection_create(request):
         if form.is_valid():
             form.save()
             return redirect('collection_list')
-    return render(request, 'forum/collection_form.html', {'form': form, 'title': '创建合集'})
+    return render(request, 'forum/collection_form.html', {'form': form})
 
 
 def collection_detail(request, collection_id):