Add custom.css and inject it into index.html

assets/custom.css

@@ -0,0 +1,47 @@
+/* Co‑op branding colors */
+:root {
+  --brand-primary-rgb: 91,140,90;   /* green */
+  --brand-surface-rgb: 250,248,245;/* cream */
+}
+
+/* Primary‑color UI */
+button,
+.primary,
+.MuiButton-contained,
+.ant-btn-primary {
+  background-color: rgb(var(--brand-primary-rgb)) !important;
+  border-color: rgb(var(--brand-primary-rgb)) !important;
+}
+
+/* Surface background */
+body,
+.appContainer,
+.chatContainer,
+.login-page {
+  background-color: rgb(var(--brand-surface-rgb)) !important;
+}
+
+/* Hide any registration / external‑account UI */
+a[href*="register"],
+a[href*="signup"],
+.register-link,
+.signup-link {
+  display: none !important;
+}
+
+/* Footer – simple centered link to the Co‑op homepage */
+footer {
+  text-align: center;
+  padding: 1rem;
+}
+footer::before {
+  content: "© Inference Co‑op – ";
+}
+footer::after {
+  content: "inference.coop";
+  color: rgb(var(--brand-primary-rgb));
+  cursor: pointer;
+}
+footer::after:hover {
+  text-decoration: underline;
+}