diff --git a/README.md b/README.md
index 5944f37..e0455ba 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@ The gallery owns one definite 720 px canvas so its nested Grid examples cannot e
 (ebox-playground-open)
 ```
 
-The package also owns the `.ebox` file boundary. Visiting an Ebox DSL file selects `ebox-dsl-mode`; press `C-c C-c` to build the single DSL form and render a preview through the public Ebox API.
+The package also owns the `.ebox` file boundary. Visiting an Ebox DSL file selects `ebox-dsl-mode`; its header line shows `C-c C-c Render preview`. Press `C-c C-c` to build the single DSL form, render it through the public Ebox API, and automatically display the preview buffer.
 
 ```elisp
 (add-to-list 'auto-mode-alist '("\\.ebox\\'" . ebox-dsl-mode))
diff --git a/README.zh-CN.md b/README.zh-CN.md
index 0d7e745..84bad85 100644
--- a/README.zh-CN.md
+++ b/README.zh-CN.md
@@ -9,7 +9,7 @@
 (ebox-playground-open)
 ```
 
-这个包也拥有 `.ebox` 文件入口。访问 Ebox DSL 文件时会自动进入 `ebox-dsl-mode`；按 `C-c C-c` 会通过 Ebox 公开 API 构建单个 DSL form 并渲染预览。
+这个包也拥有 `.ebox` 文件入口。访问 Ebox DSL 文件时会自动进入 `ebox-dsl-mode`，header line 会显示 `C-c C-c Render preview`；按 `C-c C-c` 会通过 Ebox 公开 API 构建单个 DSL form、渲染并自动弹出预览 buffer。
 
 ```elisp
 (add-to-list 'auto-mode-alist '("\\.ebox\\'" . ebox-dsl-mode))
diff --git a/ebox-playground.el b/ebox-playground.el
index da8259d..eb9cf1c 100644
--- a/ebox-playground.el
+++ b/ebox-playground.el
@@ -29,6 +29,10 @@
     map)
   "Keymap used by `ebox-dsl-mode'.")
 
+(defconst ebox-playground--dsl-header-line
+  "Ebox DSL  |  C-c C-c  Render preview"
+  "Header line shown by `ebox-dsl-mode'.")
+
 (defun ebox-playground--source-form ()
   "Read the single Ebox DSL form from the current buffer."
   (ebox-playground--evaluate-form
@@ -38,6 +42,7 @@
 ;;;###autoload
 (define-derived-mode ebox-dsl-mode emacs-lisp-mode "EboxDSL"
   "Major mode for Ebox DSL source files."
+  (setq-local header-line-format ebox-playground--dsl-header-line)
   (setq-local truncate-lines nil)
   (setq-local bidi-display-reordering nil)
   (setq-local bidi-paragraph-direction 'left-to-right))
@@ -50,7 +55,7 @@
          (name (format "*Ebox Preview: %s*"
                        (or (buffer-file-name) (buffer-name))))
          (node (ebox-build source)))
-    (ebox-render-to-buffer name node)
+    (ebox-display-buffer name node)
     (message "Rendered Ebox DSL into %s" name)
     (get-buffer name)))
 
diff --git a/tests/ebox-playground-tests.el b/tests/ebox-playground-tests.el
index 6325c09..7ebd254 100644
--- a/tests/ebox-playground-tests.el
+++ b/tests/ebox-playground-tests.el
@@ -95,7 +95,9 @@
   (with-temp-buffer
     (setq buffer-file-name "/tmp/ebox-playground-mode-test.ebox")
     (set-auto-mode)
-    (should (eq major-mode 'ebox-dsl-mode))))
+    (should (eq major-mode 'ebox-dsl-mode))
+    (should (eq (key-binding (kbd "C-c C-c")) #'ebox-dsl-render))
+    (should (string-match-p "C-c C-c" header-line-format))))
 
 (ert-deftest ebox-playground-renders-ebox-file-mode-source ()
   "Render a file-mode buffer through the public Ebox build path."
@@ -106,6 +108,8 @@
           (insert "(box :content \"Rendered from .ebox\" :width '(240))")
           (ebox-dsl-mode)
           (ebox-dsl-render)
+          (should (eq (window-buffer (selected-window))
+                      (get-buffer preview)))
           (with-current-buffer preview
             (should (string-match-p "Rendered from .ebox" (buffer-string)))))
       (when (get-buffer preview)