diff --git a/packages/frontend/src/components/MkPostForm.vue b/packages/frontend/src/components/MkPostForm.vue
index 42a3748d9aa5..6f7db13e3017 100644
--- a/packages/frontend/src/components/MkPostForm.vue
+++ b/packages/frontend/src/components/MkPostForm.vue
@@ -900,27 +900,28 @@ defineExpose({
 }
 
 .headerLeft {
-	display: grid;
-	grid-template-columns: repeat(2, minmax(36px, 50px));
-	grid-template-rows: minmax(40px, 100%);
+	display: flex;
+	flex: 0 1 100px;
 }
 
 .cancel {
 	padding: 0;
 	font-size: 1em;
 	height: 100%;
+	flex: 0 1 50px;
 }
 
 .account {
 	height: 100%;
 	display: inline-flex;
 	vertical-align: bottom;
+	flex: 0 1 50px;
 }
 
 .avatar {
 	width: 28px;
 	height: 28px;
-	margin: auto 0;
+	margin: auto;
 }
 
 .headerRight {