解决“div模式左滑菜单”页面在小分辨率手机上，按钮文字不居中的问题

examples/hello-mui/examples/offcanvas-drag-left.html

@@ -118,7 +118,7 @@
 							<span class="android-only">4、Android手机按menu键；</span>
 							</p>
 							<p style="padding: 5px 20px;margin-bottom: 5px;">
-								<button id="offCanvasShow" type="button" class="mui-btn mui-btn-primary mui-btn-block" style="padding: 5px 100px;">
+								<button id="offCanvasShow" type="button" class="mui-btn mui-btn-primary mui-btn-block" style="padding: 5px;">
 									显示侧滑菜单
 								</button>
 							</p>
@@ -163,9 +163,9 @@
 			//Android暂不支持整体移动动画
 			if(!mui.os.android){
 				document.getElementById("move-togger").classList.remove('mui-hidden');
-				var spans = document.querySelectorAll('.android-only');
-				for (var i=0,len=spans.length;i<len;i++) {
-					spans[i].style.display = "none";
+				var spans = document.querySelectorAll('.android-only');
+				for (var i=0,len=spans.length;i<len;i++) {
+					spans[i].style.display = "none";
 				}
 			}
 			
@@ -202,11 +202,11 @@
 			});
 
 
-			document.getElementById('offCanvasShow').addEventListener('tap', function() {
-				offCanvasWrapper.offCanvas('show');
-			});
-			document.getElementById('offCanvasHide').addEventListener('tap', function() {
-				offCanvasWrapper.offCanvas('close');
+			document.getElementById('offCanvasShow').addEventListener('tap', function() {
+				offCanvasWrapper.offCanvas('show');
+			});
+			document.getElementById('offCanvasHide').addEventListener('tap', function() {
+				offCanvasWrapper.offCanvas('close');
 			});
 			//主界面和侧滑菜单界面均支持区域滚动；
 			mui('#offCanvasSideScroll').scroll();