autocomplete: update style and fix #13129 (#13266)

packages/theme-chalk/src/autocomplete.scss

@@ -14,6 +14,9 @@
   margin: 5px 0;
   box-shadow: $--box-shadow-light;
   border-radius: $--border-radius-base;
+  border: 1px solid $--border-color-light;
+  overflow: hidden;
+  box-sizing: border-box;
 
   @include e(wrap) {
     max-height: 280px;
@@ -21,8 +24,6 @@
     box-sizing: border-box;
     overflow: auto;
     background-color: $--color-white;
-    border: 1px solid $--border-color-light;
-    border-radius: $--border-radius-base;
   }
 
   @include e(list) {