diff --git a/src/options.html b/src/options.html
index 9db3f24..50990c4 100644
--- a/src/options.html
+++ b/src/options.html
@@ -935,6 +935,31 @@
         font-size: 14px;
       }
 
+      .gn-conn-error {
+        padding: 48px 22px;
+        text-align: center;
+        color: var(--text-muted);
+      }
+      .gn-conn-error-icon {
+        font-size: 32px;
+        opacity: 0.4;
+        margin-bottom: 8px;
+      }
+      .gn-conn-error-title {
+        font-size: 15px;
+        font-weight: 600;
+        color: var(--text-secondary);
+        word-break: break-word;
+      }
+      .gn-conn-error-hint {
+        font-size: 13px;
+        margin-top: 6px;
+        line-height: 1.4;
+      }
+      .gn-conn-error .gn-conn-retry {
+        margin-top: 18px;
+      }
+
       /* ── View Toggle ── */
       .view-toggle {
         display: flex;
diff --git a/src/options.ts b/src/options.ts
index 4b1fcef..59773fd 100644
--- a/src/options.ts
+++ b/src/options.ts
@@ -21,6 +21,7 @@ import {
   DraftDesired,
   PlanItem,
 } from './utils/timelogDrafts';
+import { isConnectionError, renderConnectionError } from './utils/connectionError';
 
 interface WeeklyTimelog {
   issueIid: number;
@@ -2215,7 +2216,15 @@ async function loadMonth() {
     $('weekLabelTotal').textContent = formatDuration(monthTotal);
     renderCurrentView();
   } catch (err: any) {
-    content.innerHTML = `<div class="empty-state"><div class="empty-state-text" style="color:var(--red-500)">${escapeHtml(err.message)}</div></div>`;
+    if (isConnectionError(err)) {
+      renderConnectionError(content, {
+        url: gitlabUrl,
+        variant: 'options',
+        onRetry: loadMonth,
+      });
+    } else {
+      content.innerHTML = `<div class="empty-state"><div class="empty-state-text" style="color:var(--red-500)">${escapeHtml(err.message)}</div></div>`;
+    }
   }
 }
 
@@ -2690,7 +2699,15 @@ async function loadWeek() {
     $('weekLabelTotal').textContent = formatDuration(weekTotal);
     renderCurrentView();
   } catch (err: any) {
-    content.innerHTML = `<div class="empty-state"><div class="empty-state-text" style="color:var(--red-500)">${escapeHtml(err.message)}</div></div>`;
+    if (isConnectionError(err)) {
+      renderConnectionError(content, {
+        url: gitlabUrl,
+        variant: 'options',
+        onRetry: loadWeek,
+      });
+    } else {
+      content.innerHTML = `<div class="empty-state"><div class="empty-state-text" style="color:var(--red-500)">${escapeHtml(err.message)}</div></div>`;
+    }
   }
 }
 
diff --git a/src/popup.html b/src/popup.html
index 3e4abe5..711acd5 100644
--- a/src/popup.html
+++ b/src/popup.html
@@ -606,6 +606,31 @@
         font-weight: 500;
       }
 
+      .gn-conn-error {
+        padding: 32px 18px;
+        text-align: center;
+        color: var(--text-muted);
+      }
+      .gn-conn-error-icon {
+        font-size: 26px;
+        margin-bottom: 8px;
+        opacity: 0.45;
+      }
+      .gn-conn-error-title {
+        font-size: 13px;
+        font-weight: 600;
+        color: var(--text-secondary);
+        word-break: break-word;
+      }
+      .gn-conn-error-hint {
+        font-size: 12px;
+        margin-top: 4px;
+        line-height: 1.4;
+      }
+      .gn-conn-error .gn-conn-retry {
+        margin-top: 14px;
+      }
+
       .today-loading {
         padding: 36px 18px;
         text-align: center;
diff --git a/src/popup.ts b/src/popup.ts
index d0a2aa7..623663a 100644
--- a/src/popup.ts
+++ b/src/popup.ts
@@ -1,5 +1,6 @@
 import { loadThemeMode, ThemeMode } from './utils/themeManager';
 import { ESTIMATE_PRESETS, SPENT_PRESETS } from './utils/constants';
+import { isConnectionError, renderConnectionError } from './utils/connectionError';
 
 export {};
 
@@ -507,7 +508,15 @@ async function loadToday(dateStr?: string) {
     const entries = await fetchDayTimelogs(dateStr);
     renderTodayList(entries);
   } catch (err: any) {
-    list.innerHTML = `<div class="today-empty"><div class="today-empty-text" style="color:var(--red-500)">${escapeHtml(err.message)}</div></div>`;
+    if (isConnectionError(err)) {
+      renderConnectionError(list, {
+        url: tabInfo?.gitlabUrl ?? null,
+        variant: 'popup',
+        onRetry: () => loadToday(dateStr),
+      });
+    } else {
+      list.innerHTML = `<div class="today-empty"><div class="today-empty-text" style="color:var(--red-500)">${escapeHtml(err.message)}</div></div>`;
+    }
     $('todayTotal').textContent = '--';
   } finally {
     refreshBtn.disabled = false;
diff --git a/src/utils/connectionError.ts b/src/utils/connectionError.ts
new file mode 100644
index 0000000..0f4cdee
--- /dev/null
+++ b/src/utils/connectionError.ts
@@ -0,0 +1,61 @@
+/**
+ * When the GitLab instance is unreachable (VPN down, host offline, DNS failure)
+ * `fetch()` rejects with a TypeError whose message is the cryptic "Failed to
+ * fetch" rather than a normal HTTP error. These helpers detect that case and
+ * render a human-readable message plus a Retry button, instead of dumping the
+ * raw browser error onto the user.
+ */
+
+/** True when `err` looks like a network/connection failure (not an HTTP error). */
+export function isConnectionError(err: unknown): boolean {
+  if (err instanceof TypeError) return true;
+  const msg = err instanceof Error ? err.message : String(err);
+  return /failed to fetch|networkerror|network error|load failed|err_/i.test(msg);
+}
+
+/** Best-effort host label ("gitlab.example.com") for display. */
+function hostLabel(url: string | null | undefined): string {
+  if (!url) return 'your GitLab instance';
+  try {
+    return new URL(url).host;
+  } catch {
+    return url;
+  }
+}
+
+function escapeHtml(str: string): string {
+  const div = document.createElement('div');
+  div.textContent = str;
+  return div.innerHTML;
+}
+
+export interface ConnectionErrorOptions {
+  /** GitLab base URL — used to show which host could not be reached. */
+  url: string | null | undefined;
+  /** Called when the user clicks Retry. */
+  onRetry: () => void;
+  /** Picks the button class so it matches the host page's styling. */
+  variant: 'popup' | 'options';
+}
+
+/**
+ * Replaces `container`'s contents with a connection-error panel and wires up
+ * its Retry button to `onRetry`.
+ */
+export function renderConnectionError(
+  container: HTMLElement,
+  opts: ConnectionErrorOptions
+): void {
+  const host = hostLabel(opts.url);
+  const btnClass =
+    opts.variant === 'options' ? 'btn-primary' : 'onboarding-btn-primary';
+  container.innerHTML = `
+    <div class="gn-conn-error">
+      <div class="gn-conn-error-icon">&#128268;</div>
+      <div class="gn-conn-error-title">Could not connect to ${escapeHtml(host)}</div>
+      <div class="gn-conn-error-hint">Make sure it's reachable — check that your VPN is connected.</div>
+      <button type="button" class="${btnClass} gn-conn-retry">Retry</button>
+    </div>`;
+  const btn = container.querySelector<HTMLButtonElement>('.gn-conn-retry');
+  btn?.addEventListener('click', () => opts.onRetry());
+}