General fixes and additions

- Improve readability on larger and smaller screens
- Re-add page signing with a custom script (which is signed of course)
- Posts are now centered on large screens
- <code> now stops overflowing and receives a scrollbar
- The mobile page now stops to overflow

assets/css/blog.css

@@ -3,6 +3,14 @@ img {
     max-width: 800px;
 }
 
+.profile-picture {
+    max-width: 200px;
+}
+
+h1, h2, h3, h4 {
+    color: #9b59b6;
+}
+
 .post-list-item {
     display: block;
     max-width: 800px;
@@ -11,8 +19,29 @@ img {
 .post {
     display: block;
     max-width: 800px;
+
+    padding: 10px;
+
+    font-size: 21px;
+}
+
+
+@media only screen and (max-width: 768px) {
+    .post {
+        /* A smaller font looks better on smaller devices */
+        font-size: 19px;
+
+        /* Otherwise the entire page overflows for some reason */
+        width: 100%;
+    }
 }
 
 .post-title {
     color: #3498db;
 }
+
+code {
+    display: inline-block;
+    max-width: 100%;
+    overflow-y: auto;
+}