add --art-border-radius

packages/artplayer/src/style/selector.less

@@ -7,7 +7,7 @@
         justify-content: center;
         text-align: center;
         position: absolute;
-        border-radius: 3px;
+        border-radius: var(--art-border-radius);
         overflow-y: auto;
         overflow-x: hidden;
         opacity: 0;