fix: copy issue

lib/json-viewer.vue

@@ -1,5 +1,5 @@
 <template>
-  <div :class="jvClass">
+  <div ref="viewer" :class="jvClass">
     <div 
       v-if="copyable"
       :class="`jv-tooltip ${copyText.align || 'right'}`"
@@ -131,6 +131,7 @@ export default {
     }
     if (this.copyable) {
       const clipBoard = new Clipboard(this.$refs.clip, {
+        container: this.$refs.viewer,
         text: () => {
           return JSON.stringify(this.value, null, 2)
         }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "vue-json-viewer",
-  "version": "2.2.18",
+  "version": "2.2.19",
   "description": "vuejs展示json的组件",
   "main": "vue-json-viewer.js",
   "files": [