Add try/catch around `fetch()`, style system messages correctly

src/lib/Chat.svelte

@@ -62,7 +62,9 @@
     // Show updating bar
     updating = true;
 
-    const response: Response = await (
+    let response: Response;
+    try {
+      response = await (
         await fetch("https://api.openai.com/v1/chat/completions", {
           method: "POST",
           headers: {
@@ -85,6 +87,9 @@
           }),
         })
       ).json();
+    } catch (e) {
+      response = { error: { message: e.message } };
+    }
 
     // Hide updating bar
     updating = false;
@@ -214,6 +219,7 @@
     </article>
   {:else if message.role === "system"}
     <article class="message is-danger">
+      <div class="message-body">
         <SvelteMarkdown
           source={message.content}
           options={markedownOptions}
@@ -221,6 +227,7 @@
             /*code: Code*/
           }}
         />
+      </div>
     </article>
   {:else}
     <article class="message is-success">