set div content from css code example

Example 1: change text in a div css

button {
  visibility: hidden;
}
button:after {
  content:'goodbye'; 
  visibility: visible;
  display: block;
  position: absolute;
  background-color: red;
  padding: 5px;
  top: 2px;
}

Example 2: how to resize submit button in html

#search {
    width: 20em;  height: 2em;
}