javascript - Animate LENGTH of border-bottom

Question

I have a navbar. On hover of any of it menu item I want to have the exact same effect of border-bottom animation as in here (See how the border or menu items at the top-left animates when you hover them.)

I tried to find similar asked questions on stackoverflow and also on google but I didn't find anything helpful.

Any help is really appreciated.

Answer 1

Well, it was as easy as inspecting the web with the developer tools. What they do in that page is to create an element inside the menu using the :before pseudo-element. On hover they use CSS transforms (scale) to change the length.

jsfiddle.

span
{
    display: inline-block;
    padding: 6px 0px 4px;
    margin: 0px 8px 0px;
    position: relative;
}

span:before
{
    content: '';
    position: absolute;
    width: 100%;
    height: 0px;
    border-bottom: 1px solid black;
    bottom: 2px;
    -webkit-transform: scaleX(0);
    -ms-transform: scaleX(0);
    transform: scaleX(0);
    -webkit-transition: -webkit-transform 0.2s ease-in;
    transition: transform 0.2s ease-in;
}

span:hover:before
{
    -webkit-transform: scaleX(1);
    -ms-transform: scaleX(1);
    transform: scaleX(1);
}