在移动端的项目中，如果只是单纯的用px来改变字体大小是不行的，可以通过rem来控制字体的大小，但是得先写好适配。
献上代码
<!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-width:321px) and (max-width:375px){html{font-size:10px}} @media screen and (min-width:376px) and (max-width:414px){html{font-size:10px}} @media screen and (min-width:415px) and (max-width:639px){html{font-size:12px}} @media screen and (min-width:640px) and (max-width:719px){html{font-size:12px}} @media screen and (min-width:720px){html{font-size:16px}} @media screen and (min-width:750px) and (max-width:799px){html{font-size:23.5px}} @media screen and (min-width:800px)and (max-width:1199px){html{font-size:25px}} @media screen and (min-width: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>