Plan step 38: the two demo buttons are now real <x-button>s (filled for Move, text for Change the figure) instead of a hand-rolled state- layer/focus-ring button; each spring's row and its travelling dot move onto <x-surface>/<x-stack> plus data-md-showcase-motion-row/ -track/-dot in showcase.css — only the dot's size and colour are fixed there, since the transition under test stays the spring token in the view's own inline style. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9