added slide component, twwek some pages, and enchanced docs

error.vue

@@ -4,18 +4,52 @@ import type { NuxtError } from "#app";
 const property = defineProps({
     error: Object as () => NuxtError,
 });
-
-definePageMeta({
-    layout: "default",
-});
 </script>
 
 <template>
-    <NuxtLayout>
+    <NuxtLayout name="default">
         <div>
             <h1>{{ property.error?.statusCode }}</h1>
-            <p>{{ property.error?.message }}</p>
+            <h2>{{ property.error?.message }}</h2>
             <NuxtLink to="/">戻る</NuxtLink>
         </div>
     </NuxtLayout>
 </template>
+
+<style scoped>
+div {
+    display: grid;
+    width: 100vw;
+    grid-auto-flow: row;
+    place-items: center;
+    margin: 30vh 0;
+}
+
+h1 {
+    color: var(--sun4);
+    font-size: 48pt;
+}
+
+h2 {
+    color: var(--sun2);
+    font-size: 24pt;
+}
+
+a {
+    text-decoration: none;
+    color: var(--neptune1);
+    background-color: var(--starlight5);
+    font-size: 18pt;
+    padding: 0.5rem 2rem;
+    border-radius: 1rem;
+}
+
+a:visited {
+    color: var(--neptune1);
+}
+
+a:hover {
+    color: var(--neptune2);
+    background-color: var(--starlight1);
+}
+</style>