diff --git a/web/chat/chat-thread-list-item-menu.css b/web/chat/chat-thread-list-item-menu.css
new file mode 100644
--- /dev/null
+++ b/web/chat/chat-thread-list-item-menu.css
@@ -0,0 +1,55 @@
+div.sidebar .menu > button svg {
+  font-size: 16px;
+  color: var(--thread-color-read);
+}
+div.sidebar .menu {
+  opacity: 0;
+}
+div.sidebar:hover .menu {
+  display: flex;
+  align-self: flex-end;
+  opacity: 1;
+}
+.menu {
+  position: relative;
+  display: flex;
+  justify-content: flex-end;
+}
+.menu > button {
+  background-color: transparent;
+  color: var(--thread-color-read);
+  border: none;
+  cursor: pointer;
+  display: flex;
+  align-items: center;
+}
+
+.menu > button:focus {
+  outline: none;
+}
+
+.menuContent {
+  display: none;
+  position: absolute;
+  top: calc(100% + 1px);
+  right: 0;
+  z-index: 1;
+  width: max-content;
+  overflow: hidden;
+  background-color: #eeeeee;
+  border-radius: 5px;
+  box-shadow: 1px 1px 5px 2px #00000022;
+}
+.menuContentVisible {
+  display: block;
+}
+
+button.menuContent {
+  border: none;
+  cursor: pointer;
+  padding: 10px;
+  font-size: 16px;
+}
+button.menuContent:hover {
+  background-color: #dddddd;
+}
diff --git a/web/chat/chat-thread-list-item-menu.react.js b/web/chat/chat-thread-list-item-menu.react.js
--- a/web/chat/chat-thread-list-item-menu.react.js
+++ b/web/chat/chat-thread-list-item-menu.react.js
@@ -18,7 +18,7 @@
 } from 'lib/utils/action-utils';
 
 import SWMansionIcon from '../SWMansionIcon.react';
-import css from './chat-thread-list.css';
+import css from './chat-thread-list-item-menu.css';
 
 type Props = {
   +threadInfo: ThreadInfo,
diff --git a/web/chat/chat-thread-list.css b/web/chat/chat-thread-list.css
--- a/web/chat/chat-thread-list.css
+++ b/web/chat/chat-thread-list.css
@@ -147,61 +147,6 @@
   padding: 0 6px;
   font-size: 20px;
 }
-div.sidebar .menu > button svg {
-  font-size: 16px;
-  color: var(--thread-color-read);
-}
-div.sidebar .menu {
-  opacity: 0;
-}
-div.sidebar:hover .menu {
-  display: flex;
-  align-self: flex-end;
-  opacity: 1;
-}
-.menu {
-  position: relative;
-  display: flex;
-  justify-content: flex-end;
-}
-.menu > button {
-  background-color: transparent;
-  color: var(--thread-color-read);
-  border: none;
-  cursor: pointer;
-  display: flex;
-  align-items: center;
-}
-
-.menu > button:focus {
-  outline: none;
-}
-
-.menuContent {
-  display: none;
-  position: absolute;
-  top: calc(100% + 1px);
-  right: 0;
-  z-index: 1;
-  width: max-content;
-  overflow: hidden;
-  background-color: #eeeeee;
-  border-radius: 5px;
-  box-shadow: 1px 1px 5px 2px #00000022;
-}
-.menuContentVisible {
-  display: block;
-}
-
-button.menuContent {
-  border: none;
-  cursor: pointer;
-  padding: 10px;
-  font-size: 16px;
-}
-button.menuContent:hover {
-  background-color: #dddddd;
-}
 
 ul.list {
   margin: 5px 3px 10px 0px;