Fix unintentionally layered buttons

src/components/popover/popover.vue

@@ -3,14 +3,14 @@
     @mouseenter="onMouseenter"
     @mouseleave="onMouseleave"
   >
-    <button
+    <div
       ref="trigger"
       class="button-unstyled popover-trigger-button"
       type="button"
       @click="onClick"
     >
       <slot name="trigger" />
-    </button>
+    </div>
     <div
       v-if="!hidden"
       ref="content"