Improve file thumbnail channel layout

src/assets/css/chat.scss

@@ -251,6 +251,7 @@ body {
         overflow: hidden;
         text-overflow: ellipsis;
         display: -webkit-box;
+        line-clamp: 4;
         -webkit-line-clamp: 4;
         -webkit-box-orient: vertical;
       }
@@ -1612,6 +1613,16 @@ body {
   margin-bottom: $chat-standard-padding-xs;
 }
 
-.thumbnail-item .zip {
-  color: #1d1d1d;
+.thumbnail-item {
+  line-height: 16.38 * $chat-text-size;
+  .file-name {
+    font-weight: 700;
+  }
+  .file-size {
+    margin-top: 8px;
+    color: #61605F;
+  }
+  .zip {
+    color: #1d1d1d;
+  }
 }