Add dropdown style on export and import buttons

manage.html

@@ -371,10 +371,24 @@
         <summary><h2 id="backup-title" i18n-text="backupButtons"></h2></summary>
         <span id="backup-message" i18n-text="backupMessage"></span>
         <div id="backup-buttons">
-          <button id="file-all-styles" i18n-text="bckpInstStyles"></button>
+          <div class="dropdown">
-          <button id="unfile-all-styles" i18n-text="retrieveBckp"></button>
+            <button class="dropbtn"><span>Export</span> <i class="arrow down"></i></button>
-          <button id="sync-dropbox-export" i18n-text="syncDropboxStyles"></button>
+
-          <button id="sync-dropbox-import" i18n-text="retrieveDropboxSync"></button>
+            <div class="dropdown-content">
+              <a href="#" id="file-all-styles" i18n-text="bckpInstStyles"></a>
+              <a href="#" id="sync-dropbox-export" i18n-text="syncDropboxStyles"></a>
+            </div>
+          </div>
+
+          <div class="dropdown">
+            <button class="dropbtn"><span>Import</span> <i class="arrow down"></i></button>
+
+            <div class="dropdown-content">
+              <a href="#" id="unfile-all-styles" i18n-text="retrieveBckp"></a>
+              <a href="#" id="sync-dropbox-import" i18n-text="retrieveDropboxSync"></a>
+            </div>
+          </div>
+
         </div>
       </details>
 

manage/manage.css

@@ -1040,6 +1040,71 @@ input[id^="manage.newUI"] {
   text-overflow: ellipsis;
 }
 
+/* export/import buttons */
+#backup-buttons .dropbtn {
+  padding: 3px 7px;
+  cursor: pointer;
+  text-overflow: inherit;
+}
+
+#backup-buttons .dropbtn span {
+  display: inline-block;
+  margin-right: 7px;
+}
+
+#backup-buttons .dropdown {
+  position: relative;
+  display: inline-block;
+}
+
+#backup-buttons .dropdown-content {
+  display: none;
+  position: absolute;
+  background-color: #f9f9f9;
+  min-width: 160px;
+  box-shadow: 0px 8px 16px 0px rgba(0, 0, 0, 0.2);
+  z-index: 1;
+}
+
+#backup-buttons .dropdown-content a {
+  color: black;
+  padding: 12px 16px;
+  text-decoration: none;
+  display: block;
+}
+
+#backup-buttons .dropdown-content a:hover {
+  /* background-color: #f2f2f2 */
+  background-color: #e9e9e9
+}
+
+#backup-buttons .dropdown:hover .dropdown-content {
+  display: block;
+}
+
+#backup-buttons .dropdown:hover .dropbtn {
+  background-color: hsl(0, 0%, 95%);
+  border-color: hsl(0, 0%, 52%);
+  /* background-color: #3e8e41; */
+}
+
+#backup-buttons i {
+  border: solid black;
+  border-width: 0 2px 2px 0;
+  display: inline-block;
+  padding: 3px;
+}
+
+#backup-buttons .up {
+  transform: rotate(-135deg);
+  -webkit-transform: rotate(-135deg);
+}
+
+#backup-buttons .down {
+  transform: rotate(45deg);
+  -webkit-transform: rotate(45deg);
+}
+
 /* sort font */
 @font-face {
   font-family: 'sorticon';