corrected where to put margins

src/client/styles/scss/_comment_growi.scss

@@ -5,7 +5,7 @@
     margin-left: 4.5em;
 
     @include media-breakpoint-down(xs) {
-      margin-left: 0em;
+      margin-left: 3.5em;
     }
 
     // speech balloon
@@ -20,7 +20,7 @@
       border-left-width: 0;
 
       @include media-breakpoint-down(xs) {
-        display: none;
+        top: 1em;
       }
     }
   }
@@ -66,6 +66,12 @@
     // コメントセクション
     .page-comment-main {
       @extend %comment-section;
+      @include media-breakpoint-down(xs) {
+        margin-left: 0em;
+        &:before {
+          content: none;
+        }
+      }
     }
 
     // コメント本文
@@ -90,6 +96,9 @@
   .page-comment-reply-form {
     margin-right: 15px;
     margin-left: 6em;
+    @include media-breakpoint-down(xs) {
+      margin-left: 2em;
+    }
   }
   // reply button
   .btn.btn-comment-reply {