v3: error cards across the app, friendly network errors, code quality pass

src/App.css

@@ -1205,6 +1205,60 @@ body.has-player .fab-new {
   color: var(--color-danger);
 }
 
+/* ── ErrorCard ── */
+.error-card-wrap {
+  display: flex;
+  flex-direction: column;
+  gap: 0.75rem;
+}
+
+.error-card {
+  display: flex;
+  align-items: flex-start;
+  gap: 0.6rem;
+  background: var(--color-danger-bg);
+  color: var(--color-on-accent);
+  padding: 0.7rem 1rem;
+  border-radius: 8px;
+  font-size: 0.9rem;
+}
+
+.error-card-icon {
+  flex-shrink: 0;
+  line-height: 1.45;
+}
+
+.error-card-body {
+  display: flex;
+  flex-direction: column;
+  gap: 0.2rem;
+}
+
+.error-card-title {
+  margin: 0;
+  font-size: 0.95rem;
+  font-weight: 700;
+}
+
+.error-card-message {
+  margin: 0;
+  line-height: 1.45;
+  opacity: 0.85;
+}
+
+.error-card-actions {
+  display: flex;
+  align-items: center;
+  gap: 1rem;
+  flex-wrap: wrap;
+}
+
+.page-error-wrap {
+  margin: 2rem auto;
+  max-width: 480px;
+  width: 100%;
+}
+
 .form-error {
   color: var(--color-danger);
   margin: 0;
@@ -1240,27 +1294,6 @@ body.has-player .fab-new {
   padding: 4rem 1rem;
 }
 
-.page-error {
-  display: flex;
-  flex-direction: column;
-  gap: 0.75rem;
-  padding: 2rem 0;
-}
-
-.page-error-actions {
-  display: flex;
-  align-items: center;
-  gap: 1rem;
-}
-
-.error-banner {
-  background: var(--color-danger-bg);
-  color: var(--color-on-accent);
-  padding: 0.6rem 1rem;
-  border-radius: 8px;
-  font-size: 0.9rem;
-}
-
 /* ── Shared header ── */
 .app-header {
   display: flex;
@@ -1552,6 +1585,12 @@ body.has-player .fab-new {
   box-shadow: none;
 }
 
+.btn-primary:disabled {
+  opacity: 0.45;
+  cursor: not-allowed;
+  pointer-events: none;
+}
+
 .btn-secondary {
   background: none;
   border: 1px solid var(--color-border);
@@ -1635,11 +1674,6 @@ body.has-player .fab-new {
   padding: 3rem 1rem;
 }
 
-.index-status--error {
-  color: var(--color-danger);
-  opacity: 1;
-}
-
 /* ── Below-header strip (presence + sort on narrow viewports) ── */
 .index-below-header {
   display: flex;
@@ -1695,6 +1729,14 @@ body.has-player .fab-new {
   }
 }
 
+.index-page .error-card-wrap {
+  max-width: 860px;
+  width: 100%;
+  padding: 1rem 1.25rem 0;
+  box-sizing: border-box;
+  align-self: center;
+}
+
 .dump-feed {
   list-style: none;
   margin: 0;
@@ -2580,12 +2622,6 @@ body.has-player .fab-new {
   cursor: default;
 }
 
-.comment-form-error {
-  margin: 0;
-  font-size: 0.8rem;
-  color: var(--color-danger);
-}
-
 .comment-node-inner--deleted {
   opacity: 0.35;
 }

src/components/AppHeader.tsx

@@ -4,7 +4,9 @@ import { useAuth } from "../hooks/useAuth.ts";
 import { DumpCreateModal } from "./DumpCreateModal.tsx";
 import { NotificationBell } from "./NotificationBell.tsx";
 
-export function AppHeader({ centerSlot }: { centerSlot?: ReactNode }) {
+export function AppHeader(
+  { centerSlot, disableNew }: { centerSlot?: ReactNode; disableNew?: boolean },
+) {
   const { user } = useAuth();
   const navigate = useNavigate();
   const headerRef = useRef<HTMLElement>(null);
@@ -55,6 +57,8 @@ export function AppHeader({ centerSlot }: { centerSlot?: ReactNode }) {
                   type="button"
                   className="btn-primary"
                   onClick={() => setCreateModalOpen(true)}
+                  disabled={disableNew}
+                  title={disableNew ? "Server unreachable" : undefined}
                 >
                   + New
                 </button>

src/components/CommentThread.tsx

@@ -6,6 +6,7 @@ import { deserializeComment } from "../model.ts";
 import { Avatar } from "./Avatar.tsx";
 import { Markdown } from "./Markdown.tsx";
 import { relativeTime } from "../utils/relativeTime.ts";
+import { ErrorCard } from "./ErrorCard.tsx";
 
 interface CommentThreadProps {
   dumpId: string;
@@ -204,7 +205,9 @@ function CommentNode({
                 placeholder="Write a reply…"
                 rows={3}
               />
-              {replyError && <p className="comment-form-error">{replyError}</p>}
+              {replyError && (
+                <ErrorCard title="Failed to post reply" message={replyError} />
+              )}
               <div className="comment-form-actions">
                 <button
                   type="submit"
@@ -323,7 +326,7 @@ export function CommentThread({
             rows={3}
           />
           {topLevelError && (
-            <p className="comment-form-error">{topLevelError}</p>
+            <ErrorCard title="Failed to post comment" message={topLevelError} />
           )}
           <div className="comment-form-actions">
             <button

src/components/DumpCreateModal.tsx

@@ -18,6 +18,8 @@ import RichContentCard from "./RichContentCard.tsx";
 import { MediaPlayer } from "./MediaPlayer.tsx";
 import type { RichContent } from "../model.ts";
 import { PlaylistCreateForm } from "./PlaylistCreateForm.tsx";
+import { ErrorCard } from "./ErrorCard.tsx";
+import { friendlyFetchError } from "../utils/apiError.ts";
 
 const MAX_FILE_SIZE = 50 * 1024 * 1024;
 
@@ -219,8 +221,6 @@ export function DumpCreateModal({ onClose }: DumpCreateModalProps) {
         });
       }
 
-      if (!res.ok) throw new Error(`HTTP ${res.status}`);
-
       const apiResponse = await res.json();
       if (apiResponse.success) {
         const dump = deserializeDump(apiResponse.data as RawDump);
@@ -244,14 +244,11 @@ export function DumpCreateModal({ onClose }: DumpCreateModalProps) {
       } else {
         setSubmitState({
           status: "error",
-          error: apiResponse.error.message,
+          error: apiResponse.error?.message ?? "Failed to create dump.",
         });
       }
     } catch (err) {
-      setSubmitState({
+      setSubmitState({ status: "error", error: friendlyFetchError(err) });
-        status: "error",
-        error: err instanceof Error ? err.message : "Failed to create dump.",
-      });
     }
   };
 
@@ -340,7 +337,10 @@ export function DumpCreateModal({ onClose }: DumpCreateModalProps) {
 
                 <form onSubmit={handleSubmit} className="dump-form">
                   {submitState.status === "error" && (
-                    <p className="form-error">{submitState.error}</p>
+                    <ErrorCard
+                      title="Failed to post"
+                      message={submitState.error}
+                    />
                   )}
 
                   {mode === "url"

src/components/ErrorCard.tsx

@@ -0,0 +1,20 @@
+import type { ReactNode } from "react";
+
+export function ErrorCard({ title, message, actions }: {
+  title: string;
+  message: string;
+  actions?: ReactNode;
+}) {
+  return (
+    <div className="error-card-wrap">
+      <div className="error-card" role="alert">
+        <span className="error-card-icon">⚠</span>
+        <div className="error-card-body">
+          <h2 className="error-card-title">{title}</h2>
+          <p className="error-card-message">{message}</p>
+        </div>
+      </div>
+      {actions && <div className="error-card-actions">{actions}</div>}
+    </div>
+  );
+}

src/components/PageError.tsx

@@ -1,16 +1,18 @@
 import type { ReactNode } from "react";
 import { PageShell } from "./PageShell.tsx";
+import { ErrorCard } from "./ErrorCard.tsx";
 
-export function PageError({ message, actions }: {
+export function PageError(
-  message: string;
+  { title = "Something went wrong", message, actions }: {
-  actions?: ReactNode;
+    title?: string;
-}) {
+    message: string;
+    actions?: ReactNode;
+  },
+) {
   return (
     <PageShell>
-      <div className="page-error">
+      <div className="page-error-wrap">
-        <h2>Error</h2>
+        <ErrorCard title={title} message={message} actions={actions} />
-        <p>{message}</p>
-        {actions && <div className="page-error-actions">{actions}</div>}
       </div>
     </PageShell>
   );

src/components/PlaylistCreateForm.tsx

@@ -3,6 +3,7 @@ import { API_URL } from "../config/api.ts";
 import type { Playlist, RawPlaylist } from "../model.ts";
 import { deserializePlaylist } from "../model.ts";
 import { useAuth } from "../hooks/useAuth.ts";
+import { ErrorCard } from "./ErrorCard.tsx";
 
 interface PlaylistCreateFormProps {
   /** If provided, the new playlist will have this dump added to it. */
@@ -88,7 +89,7 @@ export function PlaylistCreateForm(
           Private
         </button>
       </div>
-      {error && <p className="form-error">{error}</p>}
+      {error && <ErrorCard title="Failed to create playlist" message={error} />}
       <div className="form-actions">
         <div className="form-actions-right">
           <button

src/index.css

@@ -59,7 +59,7 @@
     --color-text-muted: #94a3b8;
     --color-bg: #ffffff;
     --color-surface: #f9f9f9;
-    --color-border: #646cff;
+    --color-border: transparent;
     --color-link-hover: #747bff;
     --color-option-bg: #f5f5f5;
     --color-option-border: #cccccc;

src/pages/Dump.tsx

@@ -22,6 +22,7 @@ import { PageShell } from "../components/PageShell.tsx";
 import { PageError } from "../components/PageError.tsx";
 import { Markdown } from "../components/Markdown.tsx";
 import { CommentThread } from "../components/CommentThread.tsx";
+import { friendlyFetchError } from "../utils/apiError.ts";
 
 type DumpState =
   | { status: "loading" }
@@ -72,9 +73,10 @@ export function Dump() {
           cache: "no-store",
           headers: token ? { Authorization: `Bearer ${token}` } : {},
         });
-        if (!res.ok) throw new Error(`HTTP ${res.status}`);
-
         const apiResponse = await res.json();
+        if (!apiResponse.success) {
+          throw new Error(apiResponse.error?.message ?? "Failed to load dump");
+        }
         const dump: Dump = deserializeDump(apiResponse.data);
         setDumpState({ status: "loaded", dump });
 
@@ -83,10 +85,7 @@ export function Dump() {
           .then((r) => r.success && setOp(deserializePublicUser(r.data)))
           .catch(() => {});
       } catch (err) {
-        setDumpState({
+        setDumpState({ status: "error", error: friendlyFetchError(err) });
-          status: "error",
-          error: err instanceof Error ? err.message : "Failed to load dump",
-        });
       }
     })();
   }, [selectedDump, preloaded]);

src/pages/DumpCreate.tsx

@@ -9,6 +9,8 @@ import { formatBytes } from "../utils/format.ts";
 import { PageShell } from "../components/PageShell.tsx";
 import RichContentCard from "../components/RichContentCard.tsx";
 import { MediaPlayer } from "../components/MediaPlayer.tsx";
+import { ErrorCard } from "../components/ErrorCard.tsx";
+import { friendlyFetchError } from "../utils/apiError.ts";
 
 const MAX_FILE_SIZE = 50 * 1024 * 1024;
 
@@ -140,19 +142,17 @@ export function DumpCreate() {
         });
       }
 
-      if (!res.ok) throw new Error(`HTTP ${res.status}`);
-
       const apiResponse = await res.json();
       if (apiResponse.success) {
         navigate(`/dumps/${apiResponse.data.id}`);
       } else {
-        setState({ status: "error", error: apiResponse.error.message });
+        setState({
+          status: "error",
+          error: apiResponse.error?.message ?? "Failed to create dump.",
+        });
       }
     } catch (err) {
-      setState({
+      setState({ status: "error", error: friendlyFetchError(err) });
-        status: "error",
-        error: err instanceof Error ? err.message : "Failed to create dump.",
-      });
     }
   };
 
@@ -226,7 +226,7 @@ export function DumpCreate() {
 
         <form onSubmit={handleSubmit} className="dump-create-form dump-form">
           {state.status === "error" && (
-            <p className="form-error">{state.error}</p>
+            <ErrorCard title="Failed to post" message={state.error} />
           )}
 
           {mode === "url"

src/pages/DumpEdit.tsx

@@ -8,6 +8,7 @@ import { useRequiredAuth } from "../hooks/useAuth.ts";
 import { formatBytes } from "../utils/format.ts";
 import { PageShell } from "../components/PageShell.tsx";
 import { PageError } from "../components/PageError.tsx";
+import { friendlyFetchError } from "../utils/apiError.ts";
 import { ConfirmModal } from "../components/ConfirmModal.tsx";
 import RichContentCard from "../components/RichContentCard.tsx";
 import FilePreview from "../components/FilePreview.tsx";
@@ -41,8 +42,6 @@ export function DumpEdit() {
           cache: "no-store",
           headers: token ? { Authorization: `Bearer ${token}` } : {},
         });
-        if (!res.ok) throw new Error(`HTTP ${res.status}`);
-
         const apiResponse = await res.json();
 
         if (apiResponse.success) {
@@ -52,13 +51,13 @@ export function DumpEdit() {
           setIsPrivate(dump.isPrivate);
           setState({ status: "loaded", dump });
         } else {
-          setState({ status: "error", error: apiResponse.error.message });
+          setState({
+            status: "error",
+            error: apiResponse.error?.message ?? "Failed to load.",
+          });
         }
       } catch (err) {
-        setState({
+        setState({ status: "error", error: friendlyFetchError(err) });
-          status: "error",
-          error: err instanceof Error ? err.message : "Load failed",
-        });
       }
     })();
   }, [selectedDump]);
@@ -90,16 +89,11 @@ export function DumpEdit() {
       });
     }
 
-    if (!res.ok) {
-      setState({ status: "error", error: `Update failed (${res.status})` });
-      return;
-    }
-
     const apiResponse = await res.json();
     if (!apiResponse.success) {
       setState({
         status: "error",
-        error: apiResponse.error?.message ?? "Update failed",
+        error: apiResponse.error?.message ?? "Update failed.",
       });
       return;
     }

src/pages/Index.tsx

@@ -21,6 +21,8 @@ import {
   type User,
 } from "../model.ts";
 
+import { ErrorCard } from "../components/ErrorCard.tsx";
+import { friendlyFetchError } from "../utils/apiError.ts";
 import { useFeedCache } from "../hooks/useFeedCache.ts";
 import { useAuth } from "../hooks/useAuth.ts";
 import { useWS } from "../hooks/useWS.ts";
@@ -84,7 +86,7 @@ function FollowedSubFeed({
     return <p className="index-status">Loading…</p>;
   }
   if (state.status === "error") {
-    return <p className="index-status index-status--error">{state.error}</p>;
+    return <ErrorCard title="Failed to load" message={state.error} />;
   }
 
   const visible = state.dumps.filter((d) => !deletedDumpIds.has(d.id));
@@ -210,7 +212,7 @@ export function Index() {
       } catch (err) {
         setDumpsState({
           status: "error",
-          error: err instanceof Error ? err.message : "Failed to load",
+          error: friendlyFetchError(err),
         });
       }
     })();
@@ -248,7 +250,7 @@ export function Index() {
           .catch((err) =>
             setFollowedUsersDumps({
               status: "error",
-              error: err instanceof Error ? err.message : "Failed to load",
+              error: friendlyFetchError(err),
             })
           );
       }
@@ -284,7 +286,7 @@ export function Index() {
           .catch((err) =>
             setFollowedPlaylistsDumps({
               status: "error",
-              error: err instanceof Error ? err.message : "Failed to load",
+              error: friendlyFetchError(err),
             })
           );
       }
@@ -577,6 +579,7 @@ export function Index() {
             {tabBar}
           </div>
         }
+        disableNew={dumpsState.status === "error"}
       />
 
       {/* Shown only on narrow viewports */}
@@ -589,7 +592,7 @@ export function Index() {
       {tab !== "followed" && (
         <>
           {loading && <p className="index-status">Loading…</p>}
-          {error && <p className="index-status index-status--error">{error}</p>}
+          {error && <ErrorCard title="Failed to load" message={error} />}
 
           {!loading && !error && combined.length === 0 && (
             <p className="index-status">No dumps yet. Be the first!</p>

src/pages/Notifications.tsx

@@ -3,6 +3,7 @@ import { Link } from "react-router";
 
 import { API_URL } from "../config/api.ts";
 import { useAuth } from "../hooks/useAuth.ts";
+import { ErrorCard } from "../components/ErrorCard.tsx";
 import { useWS } from "../hooks/useWS.ts";
 import type {
   DumpUpvotedData,
@@ -17,6 +18,7 @@ import type {
 } from "../model.ts";
 import { deserializeNotification } from "../model.ts";
 import { PageShell } from "../components/PageShell.tsx";
+import { friendlyFetchError } from "../utils/apiError.ts";
 
 const PAGE_SIZE = 30;
 
@@ -210,7 +212,9 @@ export function Notifications() {
         );
       })
       .catch((err) => {
-        if (err instanceof Error && err.message === "Failed to load") {
+        if (err instanceof TypeError) {
+          setState({ status: "error", error: friendlyFetchError(err) });
+        } else if (err instanceof Error && err.message === "Failed to load") {
           setState({ status: "error", error: err.message });
         }
       });
@@ -277,8 +281,9 @@ export function Notifications() {
         </div>
 
         {state.status === "loading" && <p className="page-loading">Loading…</p>}
-        {state.status === "error" && <p className="form-error">{state.error}
+        {state.status === "error" && (
-        </p>}
+          <ErrorCard title="Failed to load" message={state.error} />
+        )}
 
         {state.status === "loaded" && state.items.length === 0 && (
           <div className="notifications-empty">

src/pages/PlaylistDetail.tsx

@@ -13,6 +13,8 @@ import { ConfirmModal } from "../components/ConfirmModal.tsx";
 import { ImagePicker } from "../components/ImagePicker.tsx";
 import { Markdown } from "../components/Markdown.tsx";
 import { FollowPlaylistButton } from "../components/FollowButton.tsx";
+import { ErrorCard } from "../components/ErrorCard.tsx";
+import { friendlyFetchError } from "../utils/apiError.ts";
 
 type LoadState =
   | { status: "loading" }
@@ -94,7 +96,7 @@ export function PlaylistDetail() {
       .catch((err) => {
         setState({
           status: "error",
-          error: err instanceof Error ? err.message : "Failed to load",
+          error: friendlyFetchError(err),
         });
       });
   };
@@ -384,7 +386,7 @@ export function PlaylistDetail() {
       setEditOpen(false);
       fetchPlaylist();
     } catch (err) {
-      setEditError(err instanceof Error ? err.message : "Save failed");
+      setEditError(friendlyFetchError(err));
     } finally {
       setEditSaving(false);
     }
@@ -578,7 +580,9 @@ export function PlaylistDetail() {
                   </>
                 )}
             </div>
-            {editError && <p className="form-error">{editError}</p>}
+            {editError && (
+              <ErrorCard title="Failed to save" message={editError} />
+            )}
           </div>
         </div>
       </div>

src/pages/UserDumps.tsx

@@ -8,6 +8,7 @@ import {
 import { Link, useParams } from "react-router";
 
 import { API_URL } from "../config/api.ts";
+import { friendlyFetchError } from "../utils/apiError.ts";
 import type { Dump, PaginatedData, PublicUser, RawDump } from "../model.ts";
 import { deserializeDump, deserializePublicUser } from "../model.ts";
 import { useAuth } from "../hooks/useAuth.ts";
@@ -69,7 +70,7 @@ export function UserDumps() {
         .catch((err) =>
           setState({
             status: "error",
-            error: err instanceof Error ? err.message : "Failed to load",
+            error: friendlyFetchError(err),
           })
         );
       return;
@@ -105,7 +106,7 @@ export function UserDumps() {
       .catch((err) =>
         setState({
           status: "error",
-          error: err instanceof Error ? err.message : "Failed to load",
+          error: friendlyFetchError(err),
         })
       );
   }, [username]);

src/pages/UserLogin.tsx

@@ -6,6 +6,8 @@ import { API_URL } from "../config/api.ts";
 import { deserializeAuthResponse } from "../model.ts";
 import { useAuth } from "../hooks/useAuth.ts";
 import { PageShell } from "../components/PageShell.tsx";
+import { ErrorCard } from "../components/ErrorCard.tsx";
+import { friendlyFetchError } from "../utils/apiError.ts";
 
 type UserLoginState =
   | { status: "idle" }
@@ -34,21 +36,19 @@ export function UserLogin() {
         body: JSON.stringify({ username, password }),
       });
 
-      if (!res.ok) throw new Error(`HTTP ${res.status}`);
-
       const apiResponse = await res.json();
 
       if (apiResponse.success) {
         login(deserializeAuthResponse(apiResponse.data));
         navigate("/");
       } else {
-        setState({ status: "error", error: apiResponse.error.message });
+        setState({
+          status: "error",
+          error: apiResponse.error?.message ?? "Login failed.",
+        });
       }
     } catch (err) {
-      setState({
+      setState({ status: "error", error: friendlyFetchError(err) });
-        status: "error",
-        error: err instanceof Error ? err.message : "Login failed.",
-      });
     }
   };
 
@@ -58,7 +58,7 @@ export function UserLogin() {
         <h1 className="auth-card-title">Log in</h1>
 
         {state.status === "error" && (
-          <div className="error-banner">{state.error}</div>
+          <ErrorCard title="Login failed" message={state.error} />
         )}
 
         <form onSubmit={handleSubmit} className="auth-form">

src/pages/UserPlaylists.tsx

@@ -8,6 +8,7 @@ import {
 import { Link, useParams } from "react-router";
 
 import { API_URL } from "../config/api.ts";
+import { friendlyFetchError } from "../utils/apiError.ts";
 import type {
   PaginatedData,
   Playlist,
@@ -105,7 +106,7 @@ export function UserPlaylists() {
         .catch((err) =>
           setState({
             status: "error",
-            error: err instanceof Error ? err.message : "Failed to load",
+            error: friendlyFetchError(err),
           })
         );
       return;
@@ -148,7 +149,7 @@ export function UserPlaylists() {
       .catch((err) =>
         setState({
           status: "error",
-          error: err instanceof Error ? err.message : "Failed to load",
+          error: friendlyFetchError(err),
         })
       );
   }, [username]);

src/pages/UserPublicProfile.tsx

@@ -24,6 +24,8 @@ import { deserializePlaylist } from "../model.ts";
 import { useFeedCache } from "../hooks/useFeedCache.ts";
 import { DumpCreateModal } from "../components/DumpCreateModal.tsx";
 import { FollowUserButton } from "../components/FollowButton.tsx";
+import { ErrorCard } from "../components/ErrorCard.tsx";
+import { friendlyFetchError } from "../utils/apiError.ts";
 
 const PAGE_SIZE = 20;
 
@@ -72,7 +74,7 @@ function InviteButton() {
       <button type="button" className="invite-btn" onClick={generate}>
         + Invite someone
       </button>
-      {error && <p className="form-error">{error}</p>}
+      {error && <ErrorCard title="Failed to generate invite" message={error} />}
     </div>
   );
 }
@@ -181,9 +183,7 @@ export function UserPublicProfile() {
         .catch((err) =>
           setState({
             status: "error",
-            error: err instanceof Error
+            error: friendlyFetchError(err),
-              ? err.message
-              : "Failed to load profile",
           })
         );
       return;
@@ -254,7 +254,7 @@ export function UserPublicProfile() {
       } catch (err) {
         setState({
           status: "error",
-          error: err instanceof Error ? err.message : "Failed to load profile",
+          error: friendlyFetchError(err),
         });
       }
     })();
@@ -551,7 +551,9 @@ export function UserPublicProfile() {
                 O.G.
               </p>
             )}
-          {avatarError && <p className="form-error">{avatarError}</p>}
+          {avatarError && (
+            <ErrorCard title="Failed to update avatar" message={avatarError} />
+          )}
           {!isOwnProfile && (
             <FollowUserButton
               targetUserId={profileUser.id}

src/pages/UserRegister.tsx

@@ -6,6 +6,8 @@ import { API_URL } from "../config/api.ts";
 import { deserializeAuthResponse } from "../model.ts";
 import { useAuth } from "../hooks/useAuth.ts";
 import { PageShell } from "../components/PageShell.tsx";
+import { ErrorCard } from "../components/ErrorCard.tsx";
+import { friendlyFetchError } from "../utils/apiError.ts";
 
 type TokenState =
   | { status: "checking" }
@@ -67,10 +69,7 @@ export function UserRegister() {
         });
       }
     } catch (err) {
-      setFormState({
+      setFormState({ status: "error", error: friendlyFetchError(err) });
-        status: "error",
-        error: err instanceof Error ? err.message : "Registration failed.",
-      });
     }
   };
 
@@ -85,11 +84,11 @@ export function UserRegister() {
   if (tokenState.status === "invalid") {
     return (
       <PageShell centered>
-        <div className="auth-card">
+        <div className="page-error-wrap">
-          <h1 className="auth-card-title">Invalid invite</h1>
+          <ErrorCard
-          <p className="auth-card-footer">
+            title="Invalid invite"
-            This invite link is missing, expired, or already used.
+            message="This invite link is missing, expired, or already used."
-          </p>
+          />
         </div>
       </PageShell>
     );
@@ -101,7 +100,7 @@ export function UserRegister() {
         <h1 className="auth-card-title">Register</h1>
 
         {formState.status === "error" && (
-          <div className="error-banner">{formState.error}</div>
+          <ErrorCard title="Registration failed" message={formState.error} />
         )}
 
         <form onSubmit={handleSubmit} className="auth-form">

src/pages/UserUpvoted.tsx

@@ -8,6 +8,7 @@ import {
 import { Link, useParams } from "react-router";
 
 import { API_URL } from "../config/api.ts";
+import { friendlyFetchError } from "../utils/apiError.ts";
 import type { Dump, PaginatedData, PublicUser, RawDump } from "../model.ts";
 import { deserializeDump, deserializePublicUser } from "../model.ts";
 import { useAuth } from "../hooks/useAuth.ts";
@@ -83,7 +84,7 @@ export function UserUpvoted() {
         .catch((err) =>
           setState({
             status: "error",
-            error: err instanceof Error ? err.message : "Failed to load",
+            error: friendlyFetchError(err),
           })
         );
       return;
@@ -121,7 +122,7 @@ export function UserUpvoted() {
       .catch((err) =>
         setState({
           status: "error",
-          error: err instanceof Error ? err.message : "Failed to load",
+          error: friendlyFetchError(err),
         })
       );
   }, [username]);

src/utils/apiError.ts

@@ -0,0 +1,10 @@
+/**
+ * Convert a caught fetch error into a human-readable message.
+ * TypeError means the request never left the client (no network / CORS / etc.).
+ */
+export function friendlyFetchError(err: unknown): string {
+  if (err instanceof TypeError) {
+    return "Could not connect to the server. Check your connection and try again.";
+  }
+  return err instanceof Error ? err.message : "An unexpected error occurred.";
+}