diff --git a/frontend/src/components/ui/FeedbackHost.astro b/frontend/src/components/ui/FeedbackHost.astro
new file mode 100644
index 0000000..c747d71
--- /dev/null
+++ b/frontend/src/components/ui/FeedbackHost.astro
@@ -0,0 +1,264 @@
+<div id="likwid-toasts" class="ui-toasts" aria-live="polite" aria-atomic="true"></div>
+
+<dialog id="likwid-dialog" class="ui-dialog">
+  <form method="dialog" class="ui-dialog-form">
+    <div class="ui-dialog-head">
+      <h3 id="likwid-dialog-title" class="ui-dialog-title"></h3>
+      <p id="likwid-dialog-message" class="ui-dialog-message"></p>
+    </div>
+
+    <div id="likwid-dialog-input-wrap" class="ui-dialog-input" style="display: none;">
+      <label class="ui-label" for="likwid-dialog-textarea" id="likwid-dialog-label"></label>
+      <textarea id="likwid-dialog-textarea" class="ui-textarea" rows="4"></textarea>
+    </div>
+
+    <div class="ui-dialog-actions">
+      <button id="likwid-dialog-cancel" class="ui-btn ui-btn-secondary" value="cancel" type="submit">Cancel</button>
+      <button id="likwid-dialog-confirm" class="ui-btn ui-btn-primary" value="confirm" type="submit">Confirm</button>
+    </div>
+  </form>
+</dialog>
+
+<script is:inline>
+  (function() {
+    const toastsEl = document.getElementById('likwid-toasts');
+    const dialogEl = document.getElementById('likwid-dialog');
+    const dialogTitleEl = document.getElementById('likwid-dialog-title');
+    const dialogMessageEl = document.getElementById('likwid-dialog-message');
+    const dialogInputWrapEl = document.getElementById('likwid-dialog-input-wrap');
+    const dialogLabelEl = document.getElementById('likwid-dialog-label');
+    const dialogTextareaEl = document.getElementById('likwid-dialog-textarea');
+    const dialogConfirmEl = document.getElementById('likwid-dialog-confirm');
+    const dialogCancelEl = document.getElementById('likwid-dialog-cancel');
+
+    function toast(type, message, opts) {
+      if (!toastsEl) return;
+
+      const options = opts || {};
+      const id = 't_' + Math.random().toString(16).slice(2);
+      const el = document.createElement('div');
+      el.className = 'ui-toast ui-toast-' + (type || 'info');
+      el.setAttribute('role', type === 'error' ? 'alert' : 'status');
+      el.dataset.toastId = id;
+
+      const text = document.createElement('div');
+      text.className = 'ui-toast-text';
+      text.textContent = String(message || '');
+
+      const close = document.createElement('button');
+      close.type = 'button';
+      close.className = 'ui-toast-close';
+      close.setAttribute('aria-label', 'Dismiss notification');
+      close.textContent = '×';
+      close.addEventListener('click', () => {
+        el.remove();
+      });
+
+      el.appendChild(text);
+      el.appendChild(close);
+      toastsEl.appendChild(el);
+
+      const timeoutMs = typeof options.timeoutMs === 'number' ? options.timeoutMs : 4500;
+      if (timeoutMs > 0) {
+        window.setTimeout(() => {
+          el.remove();
+        }, timeoutMs);
+      }
+    }
+
+    function openDialog(mode, opts) {
+      const options = opts || {};
+
+      if (!dialogEl || !dialogTitleEl || !dialogMessageEl || !dialogConfirmEl || !dialogCancelEl) {
+        return Promise.resolve(mode === 'prompt' ? null : false);
+      }
+
+      if (typeof dialogEl.showModal !== 'function') {
+        if (mode === 'prompt') {
+          return Promise.resolve(window.prompt(options.message || options.title || '', ''));
+        }
+        return Promise.resolve(window.confirm(options.message || options.title || 'Confirm?'));
+      }
+
+      dialogTitleEl.textContent = String(options.title || '');
+      dialogMessageEl.textContent = String(options.message || '');
+
+      const isPrompt = mode === 'prompt';
+      if (dialogInputWrapEl && dialogTextareaEl && dialogLabelEl) {
+        dialogInputWrapEl.style.display = isPrompt ? 'block' : 'none';
+        dialogLabelEl.textContent = String(options.label || '');
+        dialogTextareaEl.value = String(options.defaultValue || '');
+        dialogTextareaEl.placeholder = String(options.placeholder || '');
+      }
+
+      dialogConfirmEl.textContent = String(options.confirmText || (isPrompt ? 'Submit' : 'Confirm'));
+      dialogCancelEl.textContent = String(options.cancelText || 'Cancel');
+
+      return new Promise((resolve) => {
+        function cleanup() {
+          dialogEl.removeEventListener('close', onClose);
+        }
+
+        function onClose() {
+          const rv = dialogEl.returnValue;
+          if (mode === 'prompt') {
+            if (rv !== 'confirm') {
+              cleanup();
+              resolve(null);
+              return;
+            }
+            const v = dialogTextareaEl ? dialogTextareaEl.value : '';
+            cleanup();
+            resolve(v);
+            return;
+          }
+
+          cleanup();
+          resolve(rv === 'confirm');
+        }
+
+        dialogEl.addEventListener('close', onClose);
+        dialogEl.showModal();
+        if (mode === 'prompt' && dialogTextareaEl) {
+          dialogTextareaEl.focus();
+        } else {
+          dialogConfirmEl.focus();
+        }
+      });
+    }
+
+    window.likwidUi = window.likwidUi || {};
+    window.likwidUi.toast = toast;
+    window.likwidUi.confirm = function(opts) { return openDialog('confirm', opts); };
+    window.likwidUi.prompt = function(opts) { return openDialog('prompt', opts); };
+  })();
+</script>
+
+<style>
+  .ui-toasts {
+    position: fixed;
+    top: 1rem;
+    right: 1rem;
+    display: flex;
+    flex-direction: column;
+    gap: 0.75rem;
+    z-index: 9999;
+    width: min(420px, calc(100vw - 2rem));
+    pointer-events: none;
+  }
+
+  .ui-toast {
+    pointer-events: auto;
+    display: flex;
+    align-items: flex-start;
+    justify-content: space-between;
+    gap: 0.75rem;
+    padding: 0.875rem 1rem;
+    border-radius: 12px;
+    border: 1px solid var(--color-border);
+    background: color-mix(in srgb, var(--color-surface) 92%, transparent);
+    backdrop-filter: blur(10px);
+    -webkit-backdrop-filter: blur(10px);
+    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.22);
+  }
+
+  .ui-toast-text {
+    color: var(--color-text);
+    font-size: 0.9375rem;
+    line-height: 1.35;
+    white-space: pre-wrap;
+    word-break: break-word;
+  }
+
+  .ui-toast-close {
+    appearance: none;
+    background: transparent;
+    border: 0;
+    color: var(--color-text-muted);
+    font-size: 1.25rem;
+    line-height: 1;
+    cursor: pointer;
+    padding: 0;
+    margin: -2px 0 0 0;
+  }
+
+  .ui-toast-close:hover {
+    color: var(--color-text);
+  }
+
+  .ui-toast-success {
+    border-color: color-mix(in srgb, var(--color-success) 45%, var(--color-border));
+    background: color-mix(in srgb, var(--color-success-muted) 65%, var(--color-surface));
+  }
+
+  .ui-toast-error {
+    border-color: color-mix(in srgb, var(--color-error) 45%, var(--color-border));
+    background: color-mix(in srgb, var(--color-error-muted) 65%, var(--color-surface));
+  }
+
+  .ui-toast-info {
+    border-color: color-mix(in srgb, var(--color-info) 45%, var(--color-border));
+    background: color-mix(in srgb, var(--color-info-muted) 65%, var(--color-surface));
+  }
+
+  .ui-dialog {
+    border: 1px solid var(--color-border);
+    border-radius: 14px;
+    padding: 0;
+    background: var(--color-surface);
+    color: var(--color-text);
+    width: min(560px, calc(100vw - 2rem));
+  }
+
+  .ui-dialog::backdrop {
+    background: var(--color-overlay);
+  }
+
+  .ui-dialog-form {
+    padding: 1rem;
+    display: flex;
+    flex-direction: column;
+    gap: 1rem;
+  }
+
+  .ui-dialog-title {
+    margin: 0;
+    font-size: 1.05rem;
+  }
+
+  .ui-dialog-message {
+    margin: 0.25rem 0 0 0;
+    color: var(--color-text-muted);
+    font-size: 0.9375rem;
+    line-height: 1.4;
+  }
+
+  .ui-dialog-input {
+    display: flex;
+    flex-direction: column;
+    gap: 0.5rem;
+  }
+
+  .ui-label {
+    font-weight: 600;
+    font-size: 0.9375rem;
+  }
+
+  .ui-textarea {
+    width: 100%;
+    border-radius: 12px;
+    border: 1px solid var(--color-border);
+    background: var(--color-field-bg);
+    color: var(--color-text);
+    padding: 0.75rem;
+    font-size: 0.9375rem;
+    resize: vertical;
+    min-height: 88px;
+  }
+
+  .ui-dialog-actions {
+    display: flex;
+    justify-content: flex-end;
+    gap: 0.75rem;
+  }
+</style>
diff --git a/frontend/src/layouts/Layout.astro b/frontend/src/layouts/Layout.astro
index a6ec8a0..74c70a1 100644
--- a/frontend/src/layouts/Layout.astro
+++ b/frontend/src/layouts/Layout.astro
@@ -7,6 +7,7 @@ import { DEFAULT_THEME, themes as themeRegistry } from '../lib/themes';
 import { API_BASE as apiBase, SERVER_API_BASE } from '../lib/api';
 import VotingIcons from '../components/icons/VotingIcons.astro';
 import DesignSystemStyles from '../components/ui/DesignSystemStyles.astro';
+import FeedbackHost from '../components/ui/FeedbackHost.astro';
 
 function isEnabled(v: string | undefined): boolean {
   if (!v) return false;
@@ -96,6 +97,7 @@ const publicDemoSite = isEnabled((globalThis as any).process?.env?.PUBLIC_DEMO_S
   <body>
     <a class="skip-link" href="#main-content">Skip to content</a>
     <VotingIcons />
+    <FeedbackHost />
     <div class="app">
       <header class="header">
         <nav class="nav" id="site-nav">
diff --git a/frontend/src/pages/admin/approvals.astro b/frontend/src/pages/admin/approvals.astro
index 5fca9ff..6566ef3 100644
--- a/frontend/src/pages/admin/approvals.astro
+++ b/frontend/src/pages/admin/approvals.astro
@@ -168,7 +168,15 @@ import { API_BASE as apiBase } from '../../lib/api';
       btn.addEventListener('click', async () => {
         const type = btn.dataset.type;
         const id = btn.dataset.id;
-        const reason = prompt('Rejection reason (optional):');
+        const reason = window.likwidUi?.prompt
+          ? await window.likwidUi.prompt({
+              title: 'Reject request',
+              message: 'Rejection reason (optional)',
+              label: 'Reason',
+              placeholder: 'Optional',
+              confirmText: 'Reject',
+            })
+          : null;
         await reviewItem(type, id, false, reason);
       });
     });
@@ -195,7 +203,7 @@ import { API_BASE as apiBase } from '../../lib/api';
       }
 
       if (res.status === 403) {
-        alert('Admin access required');
+        window.likwidUi?.toast?.('error', 'Admin access required');
         return;
       }
 
@@ -208,7 +216,7 @@ import { API_BASE as apiBase } from '../../lib/api';
       }
 
       if (res.ok && data && data.success) {
-        alert(data.message);
+        window.likwidUi?.toast?.('success', data.message);
         // Remove item from list
         document.querySelector(`.pending-item[data-id="${id}"]`)?.remove();
         
@@ -221,10 +229,13 @@ import { API_BASE as apiBase } from '../../lib/api';
           container.innerHTML = `<p class="empty">No pending ${type} requests</p>`;
         }
       } else {
-        alert('Error: ' + ((data && (data.message || data.error)) || raw || 'Failed to process'));
+        window.likwidUi?.toast?.(
+          'error',
+          'Error: ' + ((data && (data.message || data.error)) || raw || 'Failed to process')
+        );
       }
     } catch (error) {
-      alert('Error processing request');
+      window.likwidUi?.toast?.('error', 'Error processing request');
     }
   }
 
diff --git a/frontend/src/pages/admin/invitations.astro b/frontend/src/pages/admin/invitations.astro
index 5d25666..4949f94 100644
--- a/frontend/src/pages/admin/invitations.astro
+++ b/frontend/src/pages/admin/invitations.astro
@@ -93,21 +93,21 @@ import { API_BASE as apiBase } from '../../lib/api';
       }
 
       if (res.status === 403) {
-        alert('Admin access required');
+        window.likwidUi?.toast?.('error', 'Admin access required');
         return;
       }
 
       if (res.ok) {
         const data = await res.json();
-        alert(`Invitation created!\nCode: ${data.code}`);
+        window.likwidUi?.toast?.('success', `Invitation created!\nCode: ${data.code}`, { timeoutMs: 8000 });
         (document.getElementById('email')).value = '';
         loadInvitations();
       } else {
         const err = await res.text();
-        alert('Error: ' + err);
+        window.likwidUi?.toast?.('error', 'Error: ' + err);
       }
     } catch (error) {
-      alert('Error creating invitation');
+      window.likwidUi?.toast?.('error', 'Error creating invitation');
     }
   });
 
@@ -169,13 +169,20 @@ import { API_BASE as apiBase } from '../../lib/api';
         btn.addEventListener('click', () => {
           const code = (btn).dataset.code;
           navigator.clipboard.writeText(code || '');
-          alert('Code copied to clipboard!');
+          window.likwidUi?.toast?.('success', 'Code copied to clipboard!');
         });
       });
 
       document.querySelectorAll('.js-revoke').forEach(btn => {
         btn.addEventListener('click', async () => {
-          if (!confirm('Revoke this invitation?')) return;
+          const ok = window.likwidUi?.confirm
+            ? await window.likwidUi.confirm({
+                title: 'Revoke invitation',
+                message: 'Revoke this invitation?',
+                confirmText: 'Revoke',
+              })
+            : false;
+          if (!ok) return;
           const id = (btn).dataset.id;
           try {
             const res = await fetch(`${apiBase}/api/invitations/${id}`, {
@@ -189,17 +196,17 @@ import { API_BASE as apiBase } from '../../lib/api';
             }
 
             if (res.status === 403) {
-              alert('Admin access required');
+              window.likwidUi?.toast?.('error', 'Admin access required');
               return;
             }
 
             if (res.ok) {
               loadInvitations();
             } else {
-              alert('Error: ' + (await res.text()));
+              window.likwidUi?.toast?.('error', 'Error: ' + (await res.text()));
             }
           } catch (error) {
-            alert('Error revoking invitation');
+            window.likwidUi?.toast?.('error', 'Error revoking invitation');
           }
         });
       });
diff --git a/frontend/src/pages/admin/plugins.astro b/frontend/src/pages/admin/plugins.astro
index 7b2fad9..83dcd93 100644
--- a/frontend/src/pages/admin/plugins.astro
+++ b/frontend/src/pages/admin/plugins.astro
@@ -251,21 +251,22 @@ import { API_BASE } from '../../lib/api';
           }
 
           if (res.status === 403) {
-            alert('Admin access required');
+            window.likwidUi?.toast?.('error', 'Admin access required');
             e.target.checked = !isEnabled;
             return;
           }
 
           if (!res.ok) {
             const err = await res.text();
-            alert('Failed to update plugin: ' + err);
+            window.likwidUi?.toast?.('error', 'Failed to update plugin: ' + err);
             e.target.checked = !isEnabled;
           } else {
             const card = e.target.closest('.plugin-card');
             card.classList.toggle('disabled', !isEnabled);
+            window.likwidUi?.toast?.('success', `Plugin ${isEnabled ? 'enabled' : 'disabled'}`);
           }
         } catch (err) {
-          alert('Failed to update plugin');
+          window.likwidUi?.toast?.('error', 'Failed to update plugin');
           e.target.checked = !isEnabled;
         }
       });
diff --git a/frontend/src/pages/admin/voting.astro b/frontend/src/pages/admin/voting.astro
index b79105a..22b480a 100644
--- a/frontend/src/pages/admin/voting.astro
+++ b/frontend/src/pages/admin/voting.astro
@@ -584,18 +584,21 @@ import { API_BASE } from '../../lib/api';
           }
 
           if (res.status === 403) {
-            alert('Admin access required');
+            window.likwidUi?.toast?.('error', 'Admin access required');
             e.target.checked = !isActive;
             return;
           }
 
           if (!res.ok) {
+            window.likwidUi?.toast?.('error', 'Failed to update voting method');
             e.target.checked = !isActive;
           } else {
             const row = e.target.closest('.method-row');
             row.classList.toggle('disabled', !isActive);
+            window.likwidUi?.toast?.('success', `Voting method ${isActive ? 'enabled' : 'disabled'}`);
           }
         } catch (err) {
+          window.likwidUi?.toast?.('error', 'Failed to update voting method');
           e.target.checked = !isActive;
         }
       });
@@ -622,15 +625,18 @@ import { API_BASE } from '../../lib/api';
           }
 
           if (res.status === 403) {
-            alert('Admin access required');
+            window.likwidUi?.toast?.('error', 'Admin access required');
             return;
           }
 
           if (res.ok) {
+            window.likwidUi?.toast?.('success', 'Default voting method updated');
             loadVotingMethods();
+          } else {
+            window.likwidUi?.toast?.('error', 'Failed to set default voting method');
           }
         } catch (err) {
-          console.error('Failed to set default');
+          window.likwidUi?.toast?.('error', 'Failed to set default voting method');
         }
       });
     });