style(activity): activity-detail 补充付费不退费 CSS 样式

cfc-frontend/pages/activity/activity-detail/activity-detail.vue

@@ -484,6 +484,31 @@ export default {
   line-height: 1.6;
 }
 
+/* 付费不退费说明 */
+.refund-notice {
+  margin-top: 20rpx;
+  margin-left: 30rpx;
+  margin-right: 30rpx;
+  margin-bottom: 10rpx;
+  background: #FEF2F2;
+  border: 2rpx solid #FECACA;
+  border-radius: 12rpx;
+  padding: 16rpx 20rpx;
+  display: flex;
+  flex-direction: row;
+  align-items: center;
+}
+.refund-notice-icon {
+  font-size: 24rpx;
+  margin-right: 10rpx;
+  flex-shrink: 0;
+}
+.refund-notice-text {
+  font-size: 24rpx;
+  color: #DC2626;
+  line-height: 1.4;
+}
+
 /* 底部操作栏 */
 .bottom-bar {
   position: fixed;