Add previous/next buttons for blog posts

_layouts/post.html

@@ -12,3 +12,16 @@ layout: default
 </div>
 
 {{ content }}
+
+<div class="project-footer">
+    <div>
+        {% if page.previous != nil %}
+            <a href="{{ page.previous.url }}">Previous</a>
+        {% endif %}
+    </div>
+    <div>
+        {% if page.next != nil %}
+            <a href="{{ page.next.url }}">Next</a>
+        {% endif %}
+    </div>
+</div>

assets/css/navigation.css

@@ -139,3 +139,24 @@
     margin: 0;
     display: inline-block;
 }
+
+.project-footer {
+    box-sizing: border-box;
+    display: flex;
+    flex-direction: row;
+    justify-content: space-between;
+
+    height: 64px;
+    border-top: 1px solid black;
+    border-bottom: 1px solid black;
+
+    padding-top: 16px;
+    padding-bottom: 16px;
+    margin-top: 96px;
+}
+
+.project-footer div {
+    display: flex;
+    flex-direction: row;
+    align-items: center;
+}