fixed some bugs

ios/OralTrainer/Views/RootView.swift

@@ -105,6 +105,9 @@ struct RootView: View {
                 }
             }
         }
+        .onReceive(catalogVM.$activeVideoHash) { videoHash in
+            syncCurrentCourse(with: videoHash)
+        }
         .fullScreenCover(isPresented: $showFullscreenPlayer) {
             FullscreenPlayerView(controller: controller) {
                 exitFullscreen()
@@ -264,6 +267,29 @@ struct RootView: View {
         activeModule = .train
     }
 
+    /// 训练页的课程卡片直接操作 CatalogViewModel；
+    /// 这里监听它的 activeVideoHash，保证返回课程页时高亮和“当前课程”同步。
+    private func syncCurrentCourse(with videoHash: String?) {
+        guard let videoHash else { return }
+        if let course = courses.first(where: { $0.videoHash == videoHash }) {
+            currentCourse = course
+            return
+        }
+
+        // 本地导入视频不在 /courses 列表里；仍建立当前课程信息，避免课程页状态回退。
+        if let video = catalogVM.videos.first(where: { $0.videoHash == videoHash }) {
+            currentCourse = Course(
+                videoHash: video.videoHash,
+                title: video.title,
+                durationMs: video.durationMs,
+                language: video.language,
+                sentenceCount: video.sentenceCount,
+                streamUrl: video.streamUrl,
+                enrolled: false
+            )
+        }
+    }
+
     // MARK: - Mine Page
 
     private var minePage: some View {