CSS - Overflow: Scroll; - Always show vertical scroll bar?

For anyone coming here in 2021 and later years:

"Custom scrollbars are no longer supported in iOS 14."

according to an official "Frameworks Engineer" on the developer.apple.com forums.

Please note on iPad Safari, NoviceCoding's solution won't work if you have -webkit-overflow-scrolling: touch; somewhere in your CSS. The solution is either removing all the occurrences of -webkit-overflow-scrolling: touch; or putting -webkit-overflow-scrolling: auto; with NoviceCoding's solution.

Just ran into this problem myself. OSx Lion hides scrollbars while not in use to make it seem more "slick", but at the same time the issue you addressed comes up: people sometimes cannot see whether a div has a scroll feature or not.

The fix: In your css include -

::-webkit-scrollbar {
  -webkit-appearance: none;
  width: 7px;
}

::-webkit-scrollbar-thumb {
  border-radius: 4px;
  background-color: rgba(0, 0, 0, .5);
  box-shadow: 0 0 1px rgba(255, 255, 255, .5);
}

/* always show scrollbars */

::-webkit-scrollbar {
  -webkit-appearance: none;
  width: 7px;
}

::-webkit-scrollbar-thumb {
  border-radius: 4px;
  background-color: rgba(0, 0, 0, .5);
  box-shadow: 0 0 1px rgba(255, 255, 255, .5);
}


/* css for demo */

#container {
  height: 4em;
  /* shorter than the child */
  overflow-y: scroll;
  /* clip height to 4em and scroll to show the rest */
}

#child {
  height: 12em;
  /* taller than the parent to force scrolling */
}


/* === ignore stuff below, it's just to help with the visual. === */

#container {
  background-color: #ffc;
}

#child {
  margin: 30px;
  background-color: #eee;
  text-align: center;
}

<div id="container">
  <div id="child">Example</div>
</div>

customize the apperance as needed. Source