How to hide a vertical scroll bar when not needed with CSS?

To hide a vertical scroll bar when not needed with CSS, we set the overflow property.

For instance, we write

<div><p class="scrol" id="title">-</p></div>

to add a div.

Then we write

.scrol {
  font: bold 14px Arial;
  border: 1px solid black;
  width: 100%;
  color: #616d7e;
  height: 20px;
  overflow-y: hidden;
  overflow-x: auto;
}

to set overflow-y to hidden to hide the vertical scrollbar.