diff --git a/packages/core/src/style/free-dom.scss b/packages/core/src/style/free-dom.scss
index 6555a15..5a29ce3 100644
--- a/packages/core/src/style/free-dom.scss
+++ b/packages/core/src/style/free-dom.scss
@@ -12,8 +12,15 @@
 .vv-free-dom--draggable__disabled {
   cursor: initial;
 }
-.vv-free-dom--draggable__selected,
+.vv-free-dom--draggable__selected::after,
 .vv-free-dom--draggable__selected:focus-visible {
+  content: '';
+  display: block;
+  width: 100%;
+  height: 100%;
+  position: absolute;
+  top: 0;
+  left: 0;
   background: var(--vv-free-dom--selected);
   outline: 2px dashed var(--vv-free-dom--theme);
   &::selection {
diff --git a/packages/examples/free-dom/basic/single.vue b/packages/examples/free-dom/basic/single.vue
index ef427d6..a25c34a 100644
--- a/packages/examples/free-dom/basic/single.vue
+++ b/packages/examples/free-dom/basic/single.vue
@@ -1,7 +1,7 @@
 <template>
   <section>
     <FreeDom @update:model-value="pos = $event">
-      <div>长文本长文本长文本长文本长文本长文本长文本长文本</div>
+      <div style="color: #fff; width: 100%; height: 100%; background: crimson;">长文本长文本长文本长文本长文本长文本长文本长文本</div>
     </FreeDom>
     <FreeDom :auto-size="false">
       <div>长文本长文本长文本长文本长文本长文本长文本长文本</div>