feat(csharp): handling auto-conversion error(-9)

web/documentserver-example/csharp/App_Themes/media.css

@@ -502,6 +502,17 @@
         justify-content: space-between;
         align-items: center;
     }
+    .buttonsMobile.indent {
+        margin-bottom: 0;
+        flex-wrap: nowrap;
+    }
+    .button.file-type:hover,
+    .button.file-type {
+        height: 28px;
+        width: 100px;
+        margin-bottom: 10px !important;
+        font-size: 9px;
+    }
     .button.gray{
         margin: 0;
     }

web/documentserver-example/csharp/App_Themes/stylesheet.css

@@ -230,6 +230,33 @@ label .checkbox {
     color: #FF6F3D;
 }
 
+.button.file-type {
+    font-size: 11px;
+    color: #FFFFFF;
+    padding: 8px 8px;
+    margin-right: 10px;
+}
+
+.button.file-type.disable {
+    cursor: default;
+}
+
+.button.file-type.pale {
+    opacity: 30%;
+}
+
+.button.file-type.document {
+    background: #446995;
+}
+
+.button.file-type.spreadsheet {
+    background: #40865C;
+}
+
+.button.file-type.presentation {
+    background: #AA5252;
+}
+
 .upload-panel {
     float: left;
     padding: 24px 0;
@@ -745,6 +772,16 @@ html {
     margin-left: 25px;
 }
 
+.buttonsMobile.indent{
+    padding-left: 35px;
+    margin-top: 10px;
+    margin-bottom: 10px;
+}
+
+.invisible {
+    display: none;
+}
+
 .tooltip {
     background: #FFFFFF;
     border-radius: 5px;