about scrolling the code

Hi there,
I am searching online to figure any way to introduce scroll bar when screen is small. I found that there were some posts about a similar topic dated back to at least a year ago. I also find that the author mentioned it could be fixed by modifying the css as

.EnlighterJS{
width: auto !important;
overflow-x: scroll !important;
word-wrap: normal !important;
}
.EnlighterJS li{
white-space: pre !important;
}

I wonder if this hack is still work or there will be other way to make scolling work. For my case, I try the css but it doesn’t work.