css transform transition

.selector {
  transition: transform 1s;
}CSS Transitions
CSS transitions allows you to change property values smoothly, over a given duration.

In this chapter you will learn about the following properties:

transition
transition-delay
transition-duration
transition-property
transition-timing-function

To create a transition effect, you must specify two things:

the CSS property you want to add an effect to
the duration of the effect
Note: If the duration part is not specified, the transition will have no effect, because the default value is 0.

The following example shows a 100px * 100px red <div> element. The <div> element has also specified a transition effect for the width property, with a duration of 2 seconds:

Example
div {
  width: 100px;
  height: 100px;
  background: red;
  transition: width 2s;
}

The transition effect will start when the specified CSS property (width) changes value.

Now, let us specify a new value for the width property when a user mouses over the <div> element:

Example
div:hover {
  width: 300px;
}
Notice that when the cursor mouses out of the element, it will gradually change back to its original style.

Change Several Property Values
The following example adds a transition effect for both the width and height property, with a duration of 2 seconds for the width and 4 seconds for the height:

Example
div {
  transition: width 2s, height 4s;
}