效果图：
完整代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>数字倒计时</title>
<!-- Box icons CDN -->
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/boxicons@latest/css/boxicons.min.css">
<link rel="stylesheet" href="https://unpkg.com/boxicons@latest/css/boxicons.min.css">
<style>
@import url('https://fonts.googleapis.com/css2?family=Merriweather:wght@900&family=Poppins&display=swap