404 page

src/components/Base.astro

···
   title: string;
   graph?: {
     description: string;
-    url: string;
+    url?: string;
     type?: "website" | "article";
     image?: string;
   };

src/pages/404.astro

···
+---
+import Base from "../components/Base.astro";
+import "../styles/main.css";
+import "../styles/splashscreen.css";
+---
+
+<Base
+  title="ENTRANCE"
+  graph={{
+    description: "Page not found.",
+  }}
+>
+  <div class="bwcontainer">
+    <main class="bwbox center">
+        <h1>ERROR_404</h1>
+        <p>This page doesn't exist.</p>
+        <p><a href="/home">Return home.</a></p>
+    </main>
+  </div>
+</Base>

src/styles/main.css

···
   line-height: 1.5rem;
 }
 
+p {
+  margin: 13px 0;
+}
+
 a {
+  font-size: 1rem;
   color: var(--yellow);
   text-decoration: underline dashed;
   text-underline-offset: 4px;
···
   border: 10px double var(--white);
   padding: 13px 15px;
 }
+
+.center {
+  text-align: center;
+  vertical-align: middle;
+}