mod: 侧边栏、动态重构，排行改为首页分区，平板、折叠屏、竖屏视频新适配，播放页可隐藏黑边、截图、点踩，弹幕粗细调整，默认关闭后台播放，弹窗接受返回

lib/common/widgets/overlay_pop.dart

@@ -1,4 +1,7 @@
+import 'dart:math';
+
 import 'package:flutter/material.dart';
+import 'package:get/get.dart';
 import '../../utils/download.dart';
 import '../constants.dart';
 import 'network_img_layer.dart';
@@ -11,9 +14,10 @@ class OverlayPop extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final double imgWidth = MediaQuery.sizeOf(context).width - 8 * 2;
+    final double imgWidth = min(Get.height,Get.width) - 8 * 2;
     return Container(
       margin: const EdgeInsets.symmetric(horizontal: 8),
+      width: imgWidth,
       decoration: BoxDecoration(
         color: Theme.of(context).colorScheme.background,
         borderRadius: BorderRadius.circular(10.0),
@@ -70,6 +74,7 @@ class OverlayPop extends StatelessWidget {
                     tooltip: '保存封面图',
                     onPressed: () async {
                       await DownloadUtils.downloadImg(
+                        context,
                         videoItem.pic != null
                             ? videoItem.pic as String
                             : videoItem.cover as String,