feat(invitations): redesign acceptance flow with inline auth and auto-join (closes Sentinent-AI/Sentinent#31)

src/app/components/accept-invitation/accept-invitation.css

@@ -11,7 +11,7 @@
   background: #ffffff;
   border: 1px solid #dbe4f0;
   border-radius: 24px;
-  padding: 2rem;
+  padding: 2.5rem 2rem;
   box-shadow: 0 20px 45px rgba(15, 23, 42, 0.08);
 }
 
@@ -26,7 +26,8 @@
 
 .accept-card h1 {
   margin: 0;
-  font-size: 2rem;
+  font-size: 1.9rem;
+  color: #0f172a;
 }
 
 .description {
@@ -52,31 +53,41 @@
 .summary span {
   display: block;
   color: #64748b;
+  font-size: 0.8rem;
   margin-bottom: 0.35rem;
 }
 
-.actions {
-  display: flex;
-  gap: 0.75rem;
-  align-items: center;
+.summary strong {
+  text-transform: capitalize;
 }
 
+/* Shared button styles */
 .primary-btn,
-.secondary-btn {
+.secondary-btn,
+.ghost-btn {
   display: inline-flex;
   justify-content: center;
   align-items: center;
   border-radius: 999px;
-  padding: 0.85rem 1.15rem;
+  padding: 0.75rem 1.25rem;
   font-weight: 700;
+  font-size: 0.95rem;
   text-decoration: none;
+  cursor: pointer;
+  transition: opacity 0.15s;
+}
+
+.primary-btn:disabled,
+.secondary-btn:disabled,
+.ghost-btn:disabled {
+  opacity: 0.55;
+  cursor: not-allowed;
 }
 
 .primary-btn {
   border: 1px solid #111827;
   background: #111827;
   color: #ffffff;
-  cursor: pointer;
 }
 
 .secondary-btn {
@@ -85,30 +96,147 @@
   color: #0f172a;
 }
 
+.ghost-btn {
+  border: none;
+  background: transparent;
+  color: #64748b;
+  padding-left: 0.5rem;
+  padding-right: 0.5rem;
+}
+
+.ghost-btn:hover {
+  color: #0f172a;
+}
+
+/* Action rows */
+.actions,
+.auth-choice-actions,
+.form-actions {
+  display: flex;
+  gap: 0.75rem;
+  align-items: center;
+  margin-top: 1.5rem;
+}
+
+/* Auth-choice prompt */
+.auth-prompt {
+  margin: 1.25rem 0 0;
+  color: #475569;
+  font-size: 0.9rem;
+}
+
+/* Inline form */
+.inline-form {
+  margin-top: 1.5rem;
+  display: flex;
+  flex-direction: column;
+  gap: 1rem;
+}
+
+.field {
+  display: flex;
+  flex-direction: column;
+  gap: 0.4rem;
+}
+
+.field label {
+  font-size: 0.875rem;
+  font-weight: 600;
+  color: #374151;
+}
+
+.req {
+  color: #ef4444;
+}
+
+.field input {
+  border: 1px solid #d1d5db;
+  border-radius: 12px;
+  padding: 0.7rem 0.9rem;
+  font-size: 0.95rem;
+  color: #0f172a;
+  background: #f9fafb;
+  transition: border-color 0.15s, box-shadow 0.15s;
+  outline: none;
+}
+
+.field input:focus {
+  border-color: #2563eb;
+  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
+  background: #ffffff;
+}
+
+.field input:disabled {
+  opacity: 0.6;
+  cursor: not-allowed;
+}
+
+/* Feedback banners */
+.feedback {
+  margin: 0.75rem 0 0;
+  padding: 0.85rem 1rem;
+  border-radius: 12px;
+  font-weight: 600;
+  font-size: 0.9rem;
+}
+
 .feedback.success {
-  margin: 0 0 1rem;
-  padding: 0.9rem 1rem;
-  border-radius: 14px;
   background: #ecfdf5;
   color: #166534;
-  font-weight: 600;
 }
 
+.feedback.error {
+  background: #fef2f2;
+  color: #991b1b;
+}
+
+/* Error card */
 .error-card {
   text-align: left;
 }
 
+/* Loading row */
+.loading-row {
+  display: flex;
+  align-items: center;
+  gap: 0.75rem;
+  color: #64748b;
+  margin-top: 0.5rem;
+}
+
+.spinner {
+  display: inline-block;
+  width: 18px;
+  height: 18px;
+  border: 2px solid #e2e8f0;
+  border-top-color: #2563eb;
+  border-radius: 50%;
+  animation: spin 0.75s linear infinite;
+}
+
+@keyframes spin {
+  to { transform: rotate(360deg); }
+}
+
 @media (max-width: 640px) {
   .accept-shell {
     padding: 1rem;
+    align-items: flex-start;
+    padding-top: 2rem;
   }
 
   .summary {
     grid-template-columns: 1fr;
   }
 
-  .actions {
+  .actions,
+  .auth-choice-actions,
+  .form-actions {
     flex-direction: column;
     align-items: stretch;
   }
+
+  .ghost-btn {
+    text-align: center;
+  }
 }