diff --git a/packages/client/src/lib/Board.svelte b/packages/client/src/lib/Board.svelte
index df2b716..59074d0 100644
--- a/packages/client/src/lib/Board.svelte
+++ b/packages/client/src/lib/Board.svelte
@@ -122,6 +122,10 @@
           <span class="piece piece-{piece.color}">{pieceGlyph(piece)}</span>
         {/if}
         {#if ph && !piece}
+          <!-- Phantom pieces are a pointer-only private annotation overlay;
+               there is no keyboard drag interaction. The real game stays fully
+               keyboard-operable via the square button below. -->
+          <!-- svelte-ignore a11y_no_static_element_interactions -->
           <span
             class="phantom phantom-{ph.color}"
             class:dragging={sq === dragOrigin}