<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"> <meta name="viewport" content="width=device-width,initial-scale=1,maximum-scale=1, user-scalable=no,"> <title>Examples</title> <meta name="description" content=""> <meta name="keywords" content=""> <link href="" rel="stylesheet"> <style type="text/css"> html, body{ font-size: 10px; padding: 0; margin: 0; } @media screen and (min-321px) and (max-375px){html{font-size:10px}} @media screen and (min-376px) and (max-414px){html{font-size:10px}} @media screen and (min-415px) and (max-639px){html{font-size:12px}} @media screen and (min-640px) and (max-719px){html{font-size:12px}} @media screen and (min-720px){html{font-size:16px}} @media screen and (min-750px) and (max-799px){html{font-size:23.5px}} @media screen and (min-800px)and (max-1199px){html{font-size:25px}} @media screen and (min-1200px){html{font-size:30px}} div.box{ font-size: 2rem; height: 10rem; background: black; color: white; padding: 1rem; } </style> </head> <body> <div class="box"> 请缩小窗口试试！ 通过适配，然后控制rem的大小。达到字体或者盒子的自适应 </div> </body> </html>