fix: 修复样式问题并优化消息提示方式

- 将GradeClassSelector中的硬编码文本替换为多语言变量
- 调整VideoUploadDialog2的边框样式和悬停效果
- 在addCourse3中将$message替换为showToast方法以统一消息提示

src/components/common/GradeClassSelector.vue

@@ -41,7 +41,7 @@
                     :class="{ active: selectedClasses.includes(classItem.id) }" @click="toggleClass(classItem.id)">
                     {{ classItem.name }}
                   </div>
-                  <div v-if="filteredClassOptions.length === 0" class="no-class">暂无班级</div>
+                  <div v-if="filteredClassOptions.length === 0" class="no-class">{{ lang.ssNoClass }}</div>
                 </div>
               </div>
             </div>

src/components/pages/pptEasy/addCourse3.vue

@@ -2578,7 +2578,8 @@ export default {
         typeof _pptIframe.contentWindow.window.loadContentList === "function"
       ) {
         _pptIframe.contentWindow.window.loadContentList();
-        this.$message.success(this.lang.ssAddOk);
+        // this.$message.success(this.lang.ssAddOk);
+        this.showToast(this.lang.ssAddOk);
       }
     },
     loadgetCourseDetail() {
@@ -2602,9 +2603,11 @@ export default {
       ) {
         _pptIframe.contentWindow.window.addContent(data, type);
         if (type == 2) {
-          this.$message.success(this.lang.ssModifySuccess);
+          // this.$message.success(this.lang.ssModifySuccess);
+          this.showToast(this.lang.ssModifySuccess);
         } else {
-          this.$message.success(this.lang.ssAddOk);
+          // this.$message.success(this.lang.ssAddOk);
+          this.showToast(this.lang.ssAddOk);
         }
       }
     },

src/components/pages/pptEasy/dialog/VideoUploadDialog2.vue

@@ -248,7 +248,7 @@ export default {
 	flex: 1;
 	max-width: 200px;
 	padding: 15px 20px;
-	border: 1px solid #e5e7eb;
+	border: 2px solid #e5e7eb;
 	border-radius: 8px;
 	display: flex;
 	flex-direction: column;
@@ -260,8 +260,8 @@ export default {
 }
 
 .source-option:hover {
-	background-color: #fffdfa;
-	border-color: #fffdfa;
+	background-color: #fff8f0;
+	border-color: #f8963c;
 	color: #FF9300;
 	box-shadow: 0 2px 8px rgba(40, 92, 245, 0.1);
 }
@@ -286,7 +286,7 @@ export default {
 
 .option-text {
 	font-size: 16px;
-	font-weight: 500;
+	font-weight: 600;
 	color: #333;
 	text-align: center;
 }