diff --git a/frontend/src/App.css b/frontend/src/App.css
deleted file mode 100644
index 289cd5d..0000000
--- a/frontend/src/App.css
+++ /dev/null
@@ -1,495 +0,0 @@
-/*
- * TaskFlow base styles: reset, shared primitives and design tokens.
- * Palette follows the approved mockups. Two swaps were made for WCAG 2.1 AA:
- * the mockup accent #3b82f6 only reaches 3.7:1 behind white text, so filled
- * buttons use #2563eb (5.2:1) and accent text uses #1d4ed8 (6.4:1).
- */
-
-* {
-  margin: 0;
-  padding: 0;
-  box-sizing: border-box;
-}
-
-body {
-  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial,
-    sans-serif;
-  background-color: #f8fafc;
-  color: #1e293b;
-  line-height: 1.6;
-}
-
-/* Visible only to screen readers. */
-.sr-only {
-  position: absolute;
-  width: 1px;
-  height: 1px;
-  padding: 0;
-  margin: -1px;
-  overflow: hidden;
-  clip: rect(0, 0, 0, 0);
-  white-space: nowrap;
-  border: 0;
-}
-
-/* Keyboard users can jump straight to the task list. */
-.skip-link {
-  position: absolute;
-  left: -9999px;
-  top: 0;
-  z-index: 100;
-  padding: 0.75rem 1rem;
-  background-color: #1e293b;
-  color: white;
-  border-radius: 0 0 0.375rem 0;
-  text-decoration: none;
-}
-
-.skip-link:focus {
-  left: 0;
-}
-
-/* Page-level loading and error states */
-.app-loading,
-.app-error {
-  display: flex;
-  flex-direction: column;
-  align-items: center;
-  justify-content: center;
-  min-height: 100vh;
-  padding: 2rem;
-  text-align: center;
-  gap: 0.5rem;
-}
-
-.loading-spinner {
-  border: 4px solid #e2e8f0;
-  border-left-color: #2563eb;
-  border-radius: 50%;
-  width: 40px;
-  height: 40px;
-  animation: spin 1s linear infinite;
-  margin-bottom: 1rem;
-}
-
-@keyframes spin {
-  from {
-    transform: rotate(0deg);
-  }
-  to {
-    transform: rotate(360deg);
-  }
-}
-
-.app-error h1 {
-  color: #b91c1c;
-  font-size: 1.5rem;
-  margin-bottom: 0.5rem;
-}
-
-.app-error p {
-  color: #475569;
-  max-width: 34rem;
-}
-
-.retry-button {
-  margin-top: 1rem;
-}
-
-/* Inline notices (save confirmations, failed updates) */
-.app-notice-region {
-  min-height: 0;
-}
-
-.app-notice {
-  display: flex;
-  align-items: center;
-  justify-content: space-between;
-  gap: 1rem;
-  padding: 0.75rem 1rem;
-  margin-bottom: 1rem;
-  border-radius: 0.5rem;
-  border: 1px solid transparent;
-  animation: notice-in 0.2s ease-out;
-}
-
-@keyframes notice-in {
-  from {
-    opacity: 0;
-    transform: translateY(-4px);
-  }
-  to {
-    opacity: 1;
-    transform: translateY(0);
-  }
-}
-
-.app-notice.info {
-  background-color: #eff6ff;
-  border-color: #bfdbfe;
-  color: #1e40af;
-}
-
-.app-notice.error {
-  background-color: #fef2f2;
-  border-color: #fecaca;
-  color: #b91c1c;
-}
-
-.notice-dismiss {
-  background: none;
-  border: none;
-  cursor: pointer;
-  color: inherit;
-  font-size: 1rem;
-  line-height: 1;
-  min-width: 44px;
-  min-height: 44px;
-  border-radius: 0.375rem;
-}
-
-.notice-dismiss:hover {
-  background-color: rgba(0, 0, 0, 0.05);
-}
-
-/* Buttons */
-.btn {
-  display: inline-flex;
-  align-items: center;
-  justify-content: center;
-  gap: 0.5rem;
-  padding: 0.5rem 1rem;
-  border: 1px solid transparent;
-  border-radius: 0.5rem;
-  font-size: 0.875rem;
-  font-weight: 500;
-  font-family: inherit;
-  cursor: pointer;
-  transition: background-color 0.2s, box-shadow 0.2s;
-  text-decoration: none;
-  min-height: 44px; /* WCAG 2.5.5 touch target */
-}
-
-.btn:disabled {
-  opacity: 0.6;
-  cursor: not-allowed;
-}
-
-.btn-primary {
-  background-color: #2563eb;
-  color: white;
-}
-
-.btn-primary:hover:not(:disabled) {
-  background-color: #1d4ed8;
-}
-
-.btn-secondary {
-  background-color: white;
-  color: #334155;
-  border-color: #cbd5e1;
-}
-
-.btn-secondary:hover:not(:disabled) {
-  background-color: #f1f5f9;
-}
-
-.btn-danger {
-  background-color: #b91c1c;
-  color: white;
-}
-
-.btn-danger:hover:not(:disabled) {
-  background-color: #991b1b;
-}
-
-.create-task-btn {
-  flex: none;
-  white-space: nowrap;
-}
-
-.create-icon {
-  font-size: 1.125rem;
-  font-weight: 400;
-  line-height: 1;
-}
-
-/* Icon-only actions keep a 44px hit area even though the glyph is small. */
-.btn-action {
-  background: none;
-  border: none;
-  cursor: pointer;
-  border-radius: 0.375rem;
-  transition: background-color 0.2s;
-  min-width: 44px;
-  min-height: 44px;
-  display: inline-flex;
-  align-items: center;
-  justify-content: center;
-  font-size: 1rem;
-  color: #475569;
-}
-
-.btn-action:hover:not(:disabled) {
-  background-color: #f1f5f9;
-}
-
-.btn-action.delete:hover:not(:disabled) {
-  background-color: #fef2f2;
-  color: #b91c1c;
-}
-
-.btn-action:disabled {
-  opacity: 0.5;
-  cursor: not-allowed;
-}
-
-/* One consistent, always-visible focus indicator */
-:focus-visible {
-  outline: 2px solid #2563eb;
-  outline-offset: 2px;
-}
-
-/* Avatars */
-.user-avatar {
-  width: 32px;
-  height: 32px;
-  border-radius: 50%;
-  background-color: #e2e8f0;
-  display: inline-flex;
-  align-items: center;
-  justify-content: center;
-  font-weight: 600;
-  font-size: 0.75rem;
-  color: #334155;
-  flex: none;
-}
-
-.user-avatar.sm {
-  width: 24px;
-  height: 24px;
-  font-size: 0.625rem;
-}
-
-.user-avatar.lg {
-  width: 40px;
-  height: 40px;
-  font-size: 0.875rem;
-}
-
-/* Priority: coloured dot plus label, as in the dashboard mockup */
-.priority-indicator {
-  display: inline-flex;
-  align-items: center;
-  gap: 0.5rem;
-  font-size: 0.875rem;
-  font-weight: 600;
-}
-
-.priority-dot {
-  width: 10px;
-  height: 10px;
-  border-radius: 50%;
-  flex: none;
-}
-
-.priority-indicator.low {
-  color: #1d4ed8;
-}
-
-.priority-indicator.low .priority-dot {
-  background-color: #2563eb;
-}
-
-.priority-indicator.medium {
-  color: #b45309;
-}
-
-.priority-indicator.medium .priority-dot {
-  background-color: #f59e0b;
-}
-
-.priority-indicator.high {
-  color: #b91c1c;
-}
-
-.priority-indicator.high .priority-dot {
-  background-color: #ef4444;
-}
-
-/* Status pill, doubling as the status control */
-.status-badge,
-.status-select {
-  display: inline-flex;
-  align-items: center;
-  padding: 0.375rem 0.75rem;
-  border-radius: 9999px;
-  border: 1px solid transparent;
-  font-size: 0.8125rem;
-  font-weight: 500;
-  font-family: inherit;
-}
-
-.status-select {
-  appearance: none;
-  -webkit-appearance: none;
-  cursor: pointer;
-  min-height: 32px;
-  padding-right: 1.75rem;
-  background-repeat: no-repeat;
-  background-position: right 0.5rem center;
-  background-size: 8px;
-  background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 5'%3E%3Cpath fill='%23334155' d='M0 0h8L4 5z'/%3E%3C/svg%3E");
-}
-
-.status-select:disabled {
-  opacity: 0.6;
-  cursor: progress;
-}
-
-.status-badge.open,
-.status-select.open {
-  background-color: #dbeafe;
-  color: #1d4ed8;
-}
-
-.status-badge.in_progress,
-.status-select.in_progress {
-  background-color: #fef3c7;
-  color: #92400e;
-}
-
-.status-badge.blocked,
-.status-select.blocked {
-  background-color: #fee2e2;
-  color: #b91c1c;
-}
-
-/* Assignee */
-.assignee-info {
-  display: inline-flex;
-  align-items: center;
-  gap: 0.5rem;
-}
-
-.assignee-name {
-  font-size: 0.875rem;
-  font-weight: 500;
-  color: #334155;
-}
-
-.unassigned {
-  font-size: 0.875rem;
-  color: #6b7280;
-  font-style: italic;
-}
-
-/* Due dates */
-.due-date {
-  font-size: 0.875rem;
-  color: #475569;
-}
-
-.due-date.none {
-  color: #6b7280;
-  font-style: italic;
-}
-
-.due-date.overdue {
-  color: #b91c1c;
-  font-weight: 600;
-}
-
-/* Form primitives (shared by the task dialog) */
-.form-group {
-  margin-bottom: 0.875rem;
-}
-
-.form-label {
-  display: block;
-  font-weight: 500;
-  margin-bottom: 0.375rem;
-  color: #334155;
-  font-size: 0.9375rem;
-}
-
-.form-label.required::after {
-  content: ' *';
-  color: #b91c1c;
-  font-weight: 700;
-}
-
-.form-input,
-.form-select,
-.form-textarea {
-  width: 100%;
-  padding: 0.625rem 0.75rem;
-  border: 1px solid #cbd5e1;
-  border-radius: 0.5rem;
-  font-size: 0.9375rem;
-  font-family: inherit;
-  color: #1e293b;
-  background-color: white;
-  min-height: 44px;
-}
-
-.form-textarea {
-  resize: vertical;
-  min-height: 68px;
-}
-
-.form-input::placeholder,
-.form-textarea::placeholder {
-  color: #6b7280;
-}
-
-.form-input:hover,
-.form-select:hover,
-.form-textarea:hover {
-  border-color: #94a3b8;
-}
-
-.form-input[aria-invalid='true'],
-.form-select[aria-invalid='true'],
-.form-textarea[aria-invalid='true'] {
-  border-color: #b91c1c;
-  background-color: #fffbfb;
-}
-
-.field-error {
-  margin-top: 0.375rem;
-  font-size: 0.8125rem;
-  font-weight: 500;
-  color: #b91c1c;
-}
-
-.form-hint {
-  margin-top: 0.375rem;
-  font-size: 0.8125rem;
-  color: #6b7280;
-}
-
-.required-marker {
-  color: #b91c1c;
-  font-weight: 700;
-}
-
-.form-error-banner {
-  padding: 0.75rem 1rem;
-  margin-bottom: 1.25rem;
-  border-radius: 0.5rem;
-  background-color: #fef2f2;
-  border: 1px solid #fecaca;
-  color: #b91c1c;
-  font-size: 0.875rem;
-}
-
-@media (prefers-reduced-motion: reduce) {
-  *,
-  *::before,
-  *::after {
-    animation-duration: 0.01ms !important;
-    animation-iteration-count: 1 !important;
-    transition-duration: 0.01ms !important;
-  }
-}