<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title></title> <style> .container{display: flex;align-items: center} #a{height: 500px;width: 500px;background-color: royalblue;} #b{height: 250px;width: 250px;background-color: darkblue;} </style> </head> <body> <div class="container"> <div id="a"></div> <div id="b"></div> </div> </body> </html>
如上所示三個div 內部兩個div大小不同 給外部div加上display: flex;align-items: center樣式就可使得較小的div垂直居中html