diff --git a/web/chat/chat-thread-list-item-menu.css b/web/chat/chat-thread-list-item-menu.css
new file mode 100644
index 000000000..a1e86aafc
--- /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
index 42154a3f0..2a0b4c249 100644
--- a/web/chat/chat-thread-list-item-menu.react.js
+++ b/web/chat/chat-thread-list-item-menu.react.js
@@ -1,94 +1,94 @@
 // @flow
 
 import classNames from 'classnames';
 import * as React from 'react';
 
 import {
   setThreadUnreadStatusActionTypes,
   setThreadUnreadStatus,
 } from 'lib/actions/activity-actions';
 import type {
   SetThreadUnreadStatusPayload,
   SetThreadUnreadStatusRequest,
 } from 'lib/types/activity-types';
 import type { ThreadInfo } from 'lib/types/thread-types';
 import {
   useServerCall,
   useDispatchActionPromise,
 } 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,
   +mostRecentNonLocalMessage: ?string,
   +renderStyle?: 'chat' | 'thread',
 };
 function ChatThreadListItemMenu(props: Props): React.Node {
   const { renderStyle = 'chat' } = props;
   const [menuVisible, setMenuVisible] = React.useState(false);
 
   const toggleMenu = React.useCallback(() => {
     setMenuVisible(!menuVisible);
   }, [menuVisible]);
 
   const hideMenu = React.useCallback(() => {
     setMenuVisible(false);
   }, []);
 
   const { threadInfo, mostRecentNonLocalMessage } = props;
   const dispatchActionPromise = useDispatchActionPromise();
   const boundSetThreadUnreadStatus: (
     request: SetThreadUnreadStatusRequest,
   ) => Promise<SetThreadUnreadStatusPayload> = useServerCall(
     setThreadUnreadStatus,
   );
   const toggleUnreadStatus = React.useCallback(() => {
     const { unread } = threadInfo.currentUser;
     const request = {
       threadID: threadInfo.id,
       unread: !unread,
       latestMessage: mostRecentNonLocalMessage,
     };
     dispatchActionPromise(
       setThreadUnreadStatusActionTypes,
       boundSetThreadUnreadStatus(request),
       undefined,
       {
         threadID: threadInfo.id,
         unread: !unread,
       },
     );
     hideMenu();
   }, [
     threadInfo,
     mostRecentNonLocalMessage,
     dispatchActionPromise,
     hideMenu,
     boundSetThreadUnreadStatus,
   ]);
 
   const toggleUnreadStatusButtonText = `Mark as ${
     threadInfo.currentUser.unread ? 'read' : 'unread'
   }`;
 
   const menuIconSize = renderStyle === 'chat' ? 24 : 16;
   const btnCls = classNames(css.menuContent, {
     [css.menuContentVisible]: menuVisible,
   });
   return (
     <div className={css.menu} onMouseLeave={hideMenu}>
       <button onClick={toggleMenu}>
         <SWMansionIcon icon="menu-vertical" size={menuIconSize} />
       </button>
       <div>
         <button className={btnCls} onClick={toggleUnreadStatus}>
           {toggleUnreadStatusButtonText}
         </button>
       </div>
     </div>
   );
 }
 
 export default ChatThreadListItemMenu;