fix(watermark): watermark causes a blank bar (#297)

src/hooks/web/useWatermark.ts

@@ -33,7 +33,7 @@ export function useWatermark(appendEl: Ref<HTMLElement | null> = ref(document.bo
     const div = document.createElement('div');
     div.id = id;
     div.style.pointerEvents = 'none';
-    div.style.top = '3px';
+    div.style.top = '0px';
     div.style.left = '0px';
     div.style.position = 'absolute';
     div.style.zIndex = '100000';