diff --git a/1000-hours/.vitepress/theme/style.scss b/1000-hours/.vitepress/theme/style.scss
index 0686ebb2..36e4860b 100644
--- a/1000-hours/.vitepress/theme/style.scss
+++ b/1000-hours/.vitepress/theme/style.scss
@@ -196,7 +196,25 @@ body {
     top: -0.5em;
   }
 
+  // @TODO 回头撤销对 code 的字体设置，因为 CharisSIL 不是等宽
   code {
     font-family: "CharisSIL", "DejaVu Sans Mono", "Courier New", monospace;
   }
+
+  span.pho {
+    border-radius: 4px;
+    padding: 3px 6px;
+    background-color: var(--vp-code-bg);
+    transition: color 0.25s, background-color 0.5s;
+    font-family: "CharisSIL", "DejaVu Sans Mono", "Courier New", monospace;
+    font-size: var(--vp-code-font-size);
+    color: var(--vp-code-color);
+    &.alt {
+      &::before, &::after {
+        content: "/";
+        display: inline-block;
+        width: 0.5em;
+      }
+    }
+  }
 }
diff --git a/1000-hours/sounds-of-american-english/2.1.3-ʌ.md b/1000-hours/sounds-of-american-english/2.1.3-ʌ.md
index 3564e2bf..a85a3362 100644
--- a/1000-hours/sounds-of-american-english/2.1.3-ʌ.md
+++ b/1000-hours/sounds-of-american-english/2.1.3-ʌ.md
@@ -1,12 +1,12 @@
 # 2.1.3. `ʌ/ɑː/aːr`
 
-从唇形上来看，`ʌ` 的唇形最小，`ɑːr` 的唇形最大。
+从唇形上来看，`ʌ` 的唇形最小，<span class="pho">ɑːr</span> 的唇形最大。
 
 In terms of mouth shape, the vowel sound `ʌ` requires the lips to be the most closed, while the vowel sound `ɑːr` requires the lips to be the most open.
 
 ![mouth shape of ʌ/ɑ](/images/vowels-mouth-ʌ-ɑ.svg)
 
-美音的 `ʌ` 实际上非常接近于英音的 `ə`，比如，*but* `/bʌt/`<span class="speak-word-inline" data-audio-us-male="/audios/us/but-us-male.mp3" data-audio-us-female="/audios/us/but-us-female.mp3"></span>听起来更接近于 `/bət/`。
+美音的 `ʌ` 实际上非常接近于英音的 `ə`，比如，*but* <span class="pho alt">bʌt</span> <span class="speak-word-inline" data-audio-us-male="/audios/us/but-us-male.mp3" data-audio-us-female="/audios/us/but-us-female.mp3"></span>听起来更接近于 `/bət/`。
 
 The American pronunciation of `ʌ` is actually quite similar to `ə`. For instance, the word *but*, pronounced `/bʌt/`, often sounds more like `/bət/`.