[调整] 优化 layout 组件代码结构

src/module/body/index.less

@@ -0,0 +1,8 @@
+.layui-body {
+    display: block;
+    flex: 1;
+    overflow: auto;
+    height: 100%;
+    box-sizing: border-box;
+    min-height: 300px;
+}

src/module/body/index.vue

@@ -1,24 +1,15 @@
-<template>
-  <div class="layui-body">
-    <slot />
-  </div>
-</template>
-
 <script lang="ts">
 export default {
   name: 'LayBody',
 }
 </script>
 
-<script setup name="LayBody" lang="ts"></script>
+<script setup name="LayBody" lang="ts">
+import "./index.less"
+</script>
 
-<style>
-.layui-body {
-  display: block;
-  flex: 1;
-  overflow: auto;
-  height: 100%;
-  box-sizing: border-box;
-  min-height: 300px;
-}
-</style>
+<template>
+  <div class="layui-body">
+    <slot />
+  </div>
+</template>