Fix sheet icon on index

customize.dist/src/less2/pages/page-index.less

@@ -185,7 +185,7 @@
     .cp-callout-kanban .cptools { background-color: @colortheme_kanban-bg; }
     .cp-callout-whiteboard .cptools { background-color: @colortheme_whiteboard-bg; }
     .cp-callout-drive .fa { background-color: @colortheme_drive-bg; }
-    .cp-callout-sheet .fa { background-color: @colortheme_oocell-bg; }
+    .cp-callout-sheet .cptools { background-color: @colortheme_oocell-bg; }
     .cp-hidden { display: none !important; }
     .cp-callout-more {
         display: inline-block;