Use styled modal dialogs for confirmations

static/css/components.css

@@ -489,9 +489,9 @@
   display: flex;
   align-items: center;
   justify-content: center;
-  background: rgba(0, 0, 0, 0.72);
-  backdrop-filter: blur(6px);
-  -webkit-backdrop-filter: blur(6px);
+  background: color-mix(in srgb, var(--bg-void) 44%, transparent);
+  backdrop-filter: blur(2px);
+  -webkit-backdrop-filter: blur(2px);
 }
 
 .auth-card {
@@ -559,6 +559,27 @@
   margin: 0;
 }
 
+.confirm-card {
+  max-width: 420px;
+}
+
+.confirm-card__icon--danger {
+  color: var(--red);
+  background: color-mix(in srgb, var(--red) 12%, transparent);
+  border-color: color-mix(in srgb, var(--red) 30%, transparent);
+}
+
+.confirm-card__actions {
+  width: 100%;
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: var(--space-3);
+}
+
+.confirm-card__actions .btn {
+  width: 100%;
+}
+
 /* ── Quick shortcuts ─────────────────────────────────────────────────────── */
 
 .shortcuts-container {