.login_container内有一个login_box
设置login_box居中
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Vue-router案例</title> <script src="js/vue.js"></script> <script src="js/vue-router.js"></script> <style> html,body,#app{ height: 100%; margin:0; } .login_container{ background-color: #2b4b6b; height: 100%; } .login_box{ 450px; height: 300px; background-color: #fff; border-radius: 3px; position: absolute; left: 50%; top: 50%; transform: translate(-50%,-50%); } </style> </head> <body> <div id="app"> <div class="login_container"> <div class="login_box">123</div> </div> </div> </body> </html>