how to apply transition in css all' code example

Example 1: scss transition

div {
  transition: all 0.5s ease;
  background: red;
  padding: 10px;
}
div:hover {
  background: green;
  padding: 20px;
}

Example 2: css background color transition

/* Answer to: "css background color transition" */

/*
  Transitions currently work in Safari, Chrome, Firefox, Opera and
  Internet Explorer 10+.

  The following should produce a fade effect for you on the browsers
  mentioned above:
*/

a {
    background-color: #FF0;
}

a:hover {
    background-color: #AD310B;
    -webkit-transition: background-color 1000ms linear;
    -ms-transition: background-color 1000ms linear;
    transition: background-color 1000ms linear;
}