实现功能 单击按钮后禁用该按钮; 间隔指定时间后恢复启用; 具体实现 { const START = 5; // s const TIMEOUT = 1000; // ms let btn = document.querySelector('#btn'), rawText = btn.value, count, handler = () => { if (count > 0) { btn.value=`Resume enabled in ${count--