refactor: establish local frontend workspace boundaries

OpenSpec change: evolve-frontend-stack

packages/ui/src/styles.css

@@ -0,0 +1,39 @@
+* {
+	box-sizing: border-box;
+}
+body {
+	margin: 0;
+	background: var(--wl-color-canvas);
+	color: var(--wl-color-text);
+}
+a {
+	color: inherit;
+	text-decoration: none;
+}
+
+@media (prefers-reduced-motion: no-preference) {
+	.mantine-Modal-content {
+		animation: modal-appear 220ms ease-out;
+	}
+
+	.mantine-Modal-overlay {
+		animation: modal-backdrop-appear 220ms ease-out;
+	}
+}
+
+@keyframes modal-appear {
+	from {
+		opacity: 0;
+		transform: translateY(8px) scale(0.98);
+	}
+	to {
+		opacity: 1;
+		transform: translateY(0) scale(1);
+	}
+}
+
+@keyframes modal-backdrop-appear {
+	from {
+		opacity: 0;
+	}
+}