How to implement the scroll bar on the right side of the ul list?

I saw a scroll bar on the right side of a ul, on the Tencent school enrollment website. I wanted to see how it was implemented, but I found that the structure

could not be found on the page.

want to know how this is achieved?
attach a link: https://join.qq.com/post.php?. link description

Dec.01,2021

is not all written overflow-y: auto, the style of the scroll bar can be modified through css, you can know about Baidu.

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1eb5cdc-48367.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1eb5cdc-48367.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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