Transitions

Transition in CSS is used to change values over a specified duration, animating the property changes, rather than having them occur immediately.

Examples

Adding transition on click using JS

.box {
  width: 2rem;
  transition: width 2s ease;
}

const box = document.querySelector(".box");
box.onclick = (_event) => {
  box.style.width = "10rem";
};

In this case, the box element width will be increased when the box is clicked.

Don't forget to reset width to the original value.

For changing the color on hover,

.box {
  -webkit-transition: background-color 2s ease-out;
  -moz-transition: background-color 2s ease-out;
  -o-transition: background-color 2s ease-out;
  transition: background-color 2s ease-out;
}

.box:hover {
  background-color: green;
}

In this example the color of the box will be changed gradually over the period of 2 second.

The webkit, moz and o transition is needed for cross platform working.

Examples​

Examples