const { createApp, reactive, computed } = Vue;

createApp({
  setup() {
    const course = reactive({
      title: "Vue3 响应式基础",
      totalLessons: 10,
      finishedLessons: 3,
    });

    const progressText = computed(() => {
      // 任务：返回类似 “当前已完成 3 / 10 节”
      return "";
    });

    function finishOneLesson() {
      // 任务：在不超过总课时的前提下，finishedLessons 加 1
    }

    return {
      course,
      progressText,
      finishOneLesson,
    };
  },
}).mount("#app");