diff --git a/packages/react/src/scene/atlas/atlasPoly.tsx b/packages/react/src/scene/atlas/atlasPoly.tsx
index cff10f27..4d85b3b5 100644
--- a/packages/react/src/scene/atlas/atlasPoly.tsx
+++ b/packages/react/src/scene/atlas/atlasPoly.tsx
@@ -50,10 +50,18 @@ export const TextureAtlasPoly = memo(function TextureAtlasPoly({
   const style: CSSProperties = {
     transform: formatMatrix3d(entry.atlasMatrix),
     ["--polycss-atlas-size" as string]: `${atlasCanonicalSize}px`,
-    background,
-    backgroundImage: dynamic && page?.url ? `url(${page.url})` : undefined,
-    backgroundPosition: dynamic ? atlasPosition : undefined,
-    backgroundSize: dynamic ? atlasSize : undefined,
+    // Listing the `background` shorthand alongside the `background-*` longhands
+    // in one inline style object makes React warn on every update (mixing
+    // shorthand and non-shorthand for the same property). Branch so only the
+    // current mode's keys are assigned — baked gets `background`, dynamic gets
+    // the longhands.
+    ...(dynamic
+      ? {
+          backgroundImage: page?.url ? `url(${page.url})` : undefined,
+          backgroundPosition: atlasPosition,
+          backgroundSize: atlasSize,
+        }
+      : { background }),
     ...(dynamic
       ? {
           ["--pnx" as string]: entry.normal[0].toFixed(4),
diff --git a/website/src/components/WordArtWorkbench/WordArtWorkbench.tsx b/website/src/components/WordArtWorkbench/WordArtWorkbench.tsx
index 229c9cf7..4367711c 100644
--- a/website/src/components/WordArtWorkbench/WordArtWorkbench.tsx
+++ b/website/src/components/WordArtWorkbench/WordArtWorkbench.tsx
@@ -157,6 +157,8 @@ export function WordArtWorkbench() {
   const [lightEl, setLightEl] = useState(() => qn("lel", 45));
   const [activePreset, setActivePreset] = useState<string | null>(null);
   const [exporting, setExporting] = useState(false);
+  // Mobile: only one floating panel is open at a time, toggled by the bottom tabs.
+  const [mobilePanel, setMobilePanel] = useState<"style" | "controls" | null>(null);
 
   const handleCodePen = async () => {
     const el = document.querySelector<HTMLElement>(".wa-stage .polycss-camera")
@@ -173,6 +175,13 @@ export function WordArtWorkbench() {
     }
   };
 
+  useEffect(() => {
+    if (!mobilePanel) return;
+    const onKey = (e: KeyboardEvent) => { if (e.key === "Escape") setMobilePanel(null); };
+    window.addEventListener("keydown", onKey);
+    return () => window.removeEventListener("keydown", onKey);
+  }, [mobilePanel]);
+
   // Default bundled font + Google catalog. If the URL named a font, select it
   // once the catalog is in.
   useEffect(() => {
@@ -366,7 +375,11 @@ export function WordArtWorkbench() {
         status={status}
       />
 
-      <aside className="wa-card wa-left" aria-label="Text and presets">
+      <aside
+        id="wa-style-panel"
+        className={`wa-card wa-left ${mobilePanel === "style" ? "is-mobile-open" : ""}`}
+        aria-label="Text and presets"
+      >
         <div className="wa-card__body">
           <label className="wa-field">
             <span>Text</span>
@@ -398,11 +411,37 @@ export function WordArtWorkbench() {
         </div>
       </aside>
 
-      <GuiPanel values={guiValues} set={guiSet} />
+      <GuiPanel
+        id="wa-controls-panel"
+        className={mobilePanel === "controls" ? "is-mobile-open" : ""}
+        values={guiValues}
+        set={guiSet}
+      />
 
       <button type="button" className="wa-codepen" onClick={handleCodePen} disabled={exporting}>
         {exporting ? "Exporting…" : "Open in CodePen"}
       </button>
+
+      <nav className="wa-mobile-tabs" aria-label="WordArt panels">
+        <button
+          type="button"
+          className={`wa-mobile-tabs__button ${mobilePanel === "style" ? "is-active" : ""}`}
+          aria-controls="wa-style-panel"
+          aria-expanded={mobilePanel === "style"}
+          onClick={() => setMobilePanel((cur) => (cur === "style" ? null : "style"))}
+        >
+          Style
+        </button>
+        <button
+          type="button"
+          className={`wa-mobile-tabs__button ${mobilePanel === "controls" ? "is-active" : ""}`}
+          aria-controls="wa-controls-panel"
+          aria-expanded={mobilePanel === "controls"}
+          onClick={() => setMobilePanel((cur) => (cur === "controls" ? null : "controls"))}
+        >
+          Controls
+        </button>
+      </nav>
     </div>
   );
 }
@@ -540,7 +579,7 @@ interface GuiValues {
  * are identical, not a CSS approximation. lil-gui is imperative, so we mount it
  * once and bridge its onChange → React, and React state → updateDisplay().
  */
-function GuiPanel({ values, set }: { values: GuiValues; set: (k: keyof GuiValues, v: number | string | boolean) => void }) {
+function GuiPanel({ id, className = "", values, set }: { id?: string; className?: string; values: GuiValues; set: (k: keyof GuiValues, v: number | string | boolean) => void }) {
   const hostRef = useRef<HTMLDivElement>(null);
   const cfgRef = useRef<GuiValues>({ ...values });
   const ctrlRef = useRef<Record<string, ReturnType<GUI["add"]>>>({});
@@ -592,7 +631,7 @@ function GuiPanel({ values, set }: { values: GuiValues; set: (k: keyof GuiValues
     ctrlRef.current.profileSegments?.[values.profile === "round" ? "show" : "hide"]();
   });
 
-  return <div className="wa-gui" ref={hostRef} />;
+  return <div id={id} className={`wa-gui ${className}`} ref={hostRef} />;
 }
 
 interface LeftValues {
diff --git a/website/src/components/WordArtWorkbench/wordart.css b/website/src/components/WordArtWorkbench/wordart.css
index 293e65b9..f4784bf5 100644
--- a/website/src/components/WordArtWorkbench/wordart.css
+++ b/website/src/components/WordArtWorkbench/wordart.css
@@ -122,12 +122,6 @@
 }
 textarea.wa-input { resize: vertical; line-height: 1.35; height: auto; padding: 0.4rem 0.5rem; }
 
-@media (max-width: 60rem) {
-  .wa-card { position: static; width: auto; max-height: none; margin: 12px; }
-  .wa-root { height: auto; overflow: visible; }
-  .wa-stage { position: relative; height: 56vh; inset: auto; }
-}
-
 /* Right panel = real lil-gui, themed with the /gallery's exact variables. */
 .wa-gui {
   position: absolute;
@@ -235,3 +229,69 @@ textarea.wa-input { resize: vertical; line-height: 1.35; height: auto; padding:
 }
 .wa-codepen:hover { border-color: #3a86ff; }
 .wa-codepen:disabled { opacity: 0.6; cursor: progress; }
+
+/* Bottom tab bar — desktop keeps both panels floating, so it's hidden there. */
+.wa-mobile-tabs { display: none; }
+
+/* Mobile: like /gallery — the floating panels collapse into bottom sheets that
+   the tab bar toggles one at a time, over a full-bleed stage. */
+@media (max-width: 760px) {
+  .wa-root { --wa-tabs-h: 52px; }
+
+  .dn-stats-overlay { display: none !important; }
+
+  /* Only the two top-level floating panels collapse — not the left card's own
+     inline lil-gui (.wa-gui--inline), which stays inside the scrolling card. */
+  .wa-left,
+  .wa-gui:not(.wa-gui--inline) {
+    top: 8px;
+    right: 8px;
+    bottom: calc(8px + var(--wa-tabs-h) + 8px);
+    left: 8px;
+    width: auto;
+    max-width: none;
+    max-height: none;
+    z-index: 25;
+    display: none;
+  }
+  .wa-left.is-mobile-open { display: flex; }
+  .wa-gui:not(.wa-gui--inline).is-mobile-open { display: flex; flex-direction: column; }
+  .wa-left .wa-card__body { flex: 1; max-height: none; }
+
+  /* The right panel's lil-gui fills the sheet and scrolls inside it. */
+  .wa-gui:not(.wa-gui--inline) .lil-gui.root {
+    width: 100% !important;
+    height: 100% !important;
+    max-height: 100% !important;
+  }
+
+  .wa-codepen,
+  .wa-stage-foot { bottom: calc(8px + var(--wa-tabs-h) + 8px); }
+
+  .wa-mobile-tabs {
+    position: absolute;
+    right: 8px;
+    bottom: 8px;
+    left: 8px;
+    z-index: 30;
+    display: grid;
+    grid-template-columns: repeat(2, minmax(0, 1fr));
+    gap: 8px;
+  }
+  .wa-mobile-tabs__button {
+    min-height: 44px;
+    border: 1px solid #2a3340;
+    border-radius: 8px;
+    background: rgba(17, 20, 26, 0.92);
+    color: #d8e2ec;
+    font: 700 13px/1 system-ui, sans-serif;
+    cursor: pointer;
+    backdrop-filter: blur(8px);
+    -webkit-backdrop-filter: blur(8px);
+  }
+  .wa-mobile-tabs__button.is-active {
+    border-color: #22d3ee;
+    background: #12313a;
+    color: #ecfeff;
+  }
+}