diff --git a/content/dl4traj/_index.md b/content/dl4traj/_index.md
index 7240ec2..b15d89d 100644
--- a/content/dl4traj/_index.md
+++ b/content/dl4traj/_index.md
@@ -1,10 +1,11 @@
 +++
 title = "Deep Learning for Trajectory"
-sort_by = "date"
+sort_by = "none"
 paginate_by = 10
 
 [extra]
 abbr = "DL4traj"
+use_chapter_sort = true
 +++
 
 Deep learning approaches for analysis and utilization of spatiotemporal trajectories.
diff --git a/content/dl4traj/end-to-end/index.md b/content/dl4traj/end-to-end/index.md
index e170eb3..df0d09f 100644
--- a/content/dl4traj/end-to-end/index.md
+++ b/content/dl4traj/end-to-end/index.md
@@ -2,6 +2,9 @@
 title = "End-to-end Learning of Trajectories"
 date = 2026-02-02
 description = ""
+
+[extra]
+chapter = "2"
 +++
 
 End-to-end learning means training a model to perform a task from input to output, supervising only on how the output aligns with the task's ground truth.
diff --git a/content/dl4traj/generation/index.md b/content/dl4traj/generation/index.md
index 8753c23..cc49d0b 100644
--- a/content/dl4traj/generation/index.md
+++ b/content/dl4traj/generation/index.md
@@ -2,6 +2,9 @@
 title = "Trajectory Generation"
 date = 2026-02-04
 description = ""
+
+[extra]
+chapter = "4"
 +++
 
 Trajectory generation, or trajectory synthesis, aims to generate trajectories that are not actually recorded in the available trajectory data, but are still realistic and follow a target distribution.
diff --git a/content/dl4traj/introduction/index.md b/content/dl4traj/introduction/index.md
index 722468c..49705d3 100644
--- a/content/dl4traj/introduction/index.md
+++ b/content/dl4traj/introduction/index.md
@@ -2,6 +2,9 @@
 title = "Introduction to Deep Learning for Trajectories"
 date = 2026-02-01
 description = ""
+
+[extra]
+chapter = "1"
 +++
 
 A spatiotemporal trajectory is a sequence, with each item being a timestamped location. It records the movement of an object or a human through time and space.
diff --git a/content/dl4traj/self-supervised/index.md b/content/dl4traj/self-supervised/index.md
index f121b3b..d6e95f5 100644
--- a/content/dl4traj/self-supervised/index.md
+++ b/content/dl4traj/self-supervised/index.md
@@ -2,6 +2,9 @@
 title = "Self-supervised Learning of Trajectories"
 date = 2026-02-03
 description = ""
+
+[extra]
+chapter = "3"
 +++
 
 Self-supervised learning means training a model with unlabeled data, using supervisory signals extracted from the data itself. It usually does not set the model to perform a certain task, but aims to learn task-agnostic information in the data.
diff --git a/sass/style.scss b/sass/style.scss
index 3876ac7..fb0575d 100644
--- a/sass/style.scss
+++ b/sass/style.scss
@@ -138,9 +138,16 @@ ul, ol {
     gap: 1rem;
     margin-bottom: 0.5rem;
 
-    time {
+    time, .chapter {
       color: var(--muted);
       font-size: 0.9rem;
+    }
+
+    .chapter {
+      min-width: 2rem;
+    }
+
+    time {
       min-width: 6rem;
     }
   }
diff --git a/templates/section.html b/templates/section.html
index df2dc96..6f1b4da 100644
--- a/templates/section.html
+++ b/templates/section.html
@@ -17,21 +17,31 @@
 {% else %}
 {% set pages = section.pages %}
 {% endif %}
+{% if section.extra.use_chapter_sort %}
+{% set pages = pages | sort(attribute="extra.chapter") %}
+{% for page in pages %}
+    <li>
+        <span class="chapter">{{ page.extra.chapter }}</span>
+        <a href="{{ page.permalink }}">{{ page.title }}</a>
+    </li>
+{% endfor %}
+{% else %}
 {% for page in pages %}
     <li>
         <time datetime="{{ page.date }}">{{ page.date | date(format="%Y-%m-%d") }}</time>
         <a href="{{ page.permalink }}">{{ page.title }}</a>
     </li>
 {% endfor %}
+{% endif %}
 </ul>
 
 {% if paginator %}
 <nav class="pagination">
     {% if paginator.previous %}
-        <a href="{{ paginator.previous }}">&larr; Newer</a>
+        <a href="{{ paginator.previous }}">&larr; {% if section.extra.use_chapter_sort %}Previous{% else %}Newer{% endif %}</a>
     {% endif %}
     {% if paginator.next %}
-        <a href="{{ paginator.next }}">Older &rarr;</a>
+        <a href="{{ paginator.next }}">{% if section.extra.use_chapter_sort %}Next{% else %}Older{% endif %} &rarr;</a>
     {% endif %}
 </nav>
 {% endif %}