Add custom 404 page

nginx.conf

@@ -42,14 +42,24 @@ http {
 
         add_header Content-Security-Policy "default-src 'self'";
 
+        error_page 404 /404.html
+
+        location /404.html {
+            root /err/;
+        }
+
         location / {
             root /usr/share/nginx/html;
             index index.html;
             gzip_static on;
             brotli_static on;
             error_page 500 502 503 504 /50x.html;
-            try_files $uri $uri.html $uri/ =404;
+            try_files $uri.html $uri $uri/ =404;
             add_header Cache-Control "public, no-transform, max-age=1209600";
+
+            if ($uri ~* \.html$) {
+                return 404;
+            }
         }
 
         location /misc/ {

src/routes/err/404/+page.svelte

@@ -0,0 +1,23 @@
+<script lang="ts">
+  import Header from "$lib/navigation/header.svelte";
+  import Nav from "$lib/navigation/nav.svelte";
+
+    const title = "404 - Not Found"
+</script>
+
+<Header {title} />
+<h1 class="heading">There's no light at the end of this tunnel</h1>
+<p>The page you were looking for wasn't found</p>
+<p>Use the menu bar to try another destination</p>
+<br>
+<p class="err_code">Status: 404<br>Message: NOT_FOUND</p>
+<Nav />
+
+<style>
+    .heading {
+        color: var(--second-text-color);
+    }
+    .err_code {
+        color: white;
+    }
+</style>