:art: fix https://github.com/siyuan-note/siyuan/issues/11032

app/src/protyle/render/av/render.ts

@@ -193,9 +193,9 @@ ${cell.color ? `color:${cell.color};` : ""}">${renderCell(cell.value, rowIndex)}
                 });
                 let avBackground = '--av-background:var(--b3-theme-background)'
                 if (e.style.backgroundColor) {
-                    avBackground = avBackground + e.style.backgroundColor
+                    avBackground = '--av-background:' + e.style.backgroundColor
                 } else if (hasClosestByAttribute(e, "data-type", "NodeBlockQueryEmbed")) {
-                    avBackground = avBackground + 'var(--b3-theme-surface)'
+                    avBackground = '--av-background:var(--b3-theme-surface)'
                 }
                 e.firstElementChild.outerHTML = `<div class="av__container" style="${avBackground}">
     <div class="av__header">