add documentInit

packages/artplayer/src/style/progress.less

@@ -55,6 +55,9 @@
                     .art-center();
                     position: absolute;
                     z-index: 40;
+                    left: calc(var(--art-indicator-size) / -2);
+                    width: var(--art-indicator-size);
+                    height: var(--art-indicator-size);
                     border-radius: 50%;
                     transform: scale(0);
                     transition: transform var(--art-duration) ease;