添加h3标题样式确保独占一行

- 添加display: block、width: 100%和clear: both
- 确保查询条件标题独占一行，避免与查询控件重叠

vue-frontend/src/components/RoleManagement.vue

@@ -723,6 +723,9 @@ export default {
   margin: 0 0 12px 0;
   font-size: 15px;
   color: #606266;
+  display: block;
+  width: 100%;
+  clear: both;
 }
 
 .search-form {
@@ -746,7 +749,7 @@ export default {
 .search-actions {
   display: flex;
   gap: 8px;
-  margin-left: 12px;
+  margin-left: auto;
 }
 
 .action-section {