Use CSS3 transitions with gradient backgrounds

Question

I\'m trying to transition on hover with css over a thumbnail so that on hover, the background gradient fades in. The transition isn\'t working, but if I simply change it to

Answer 1

For what it's worth, here's a Sass mixin:

Usage:

@include gradientAnimation(red, blue, .6s);

Mixin:

@mixin gradientAnimation( $start, $end, $transTime ){
    background-size: 100%;
    background-image: linear-gradient($start, $end);
    position: relative;
    z-index: 100;
    &:before {
        background-image: linear-gradient($end, $start);
        content: "";
        display: block;
        height: 100%;
        position: absolute;
        top: 0; left: 0;
        opacity: 0;
        width: 100%;
        z-index: -100;
        transition: opacity $transTime;
    }
    &:hover {
        &:before {
            opacity: 1;
        }
    }
}

Taken from this awesome post on Medium from Dave Lunny: https://medium.com/@dave_lunny/animating-css-gradients-using-only-css-d2fd7671e759

Answer 2

I wanted to have a div appear like a 3D sphere and transition through colors. I discovered that gradient background colors don't transition (yet). I placed a radial gradient background in front of the element (using z-index) with a transitioning solid background.

/* overlay */
z-index : 1;
background : radial-gradient( ellipse at 25% 25%, rgba( 255, 255, 255, 0 ) 0%, rgba( 0, 0, 0, 1 ) 100% );

then the div.ball underneath:

transition : all 1s cubic-bezier(0.25, 0.46, 0.45, 0.94);

then changed the background color of the div.ball and voila!

https://codepen.io/keldon/pen/dzPxZP

Answer 3

In the following, an anchor tag has a child and a grandchild. The grandchild has the far background gradient. The child in the near background is transparent, but has the gradient to transition to. On hover, the child's opacity is transitioned from 0 to 1, over a period of 1 second.

Here is the CSS:

.bkgrndfar {
  position:absolute;
  top:0;
  left:0;
  z-index:-2;
  height:100%;
  width:100%;
  background:linear-gradient(#eee, #aaa);
}

.bkgrndnear {
  position:absolute;
  top:0;
  left:0;
  height:100%;
  width:100%;
  background:radial-gradient(at 50% 50%, blue 1%, aqua 100%);
  opacity:0;
  transition: opacity 1s;
}

a.menulnk {
  position:relative;
  text-decoration:none;
  color:#333;
  padding: 0 20px;
  text-align:center;
  line-height:27px;
  float:left;
}

a.menulnk:hover {
  color:#eee;
  text-decoration:underline;
}

/* This transitions child opacity on parent hover */
a.menulnk:hover .bkgrndnear {
  opacity:1;
}

And, this is the HTML:

<a href="#" class="menulnk">Transgradient
<div class="bkgrndfar">
  <div class="bkgrndnear">
  </div>
</div>
</a>

The above is only tested in the latest version of Chrome. These are the before hover, halfway on-hover and fully transitioned on-hover images:

Answer 4

You can FAKE transitions between gradients, using transitions in the opacity of a few stacked gradients, as described in a few of the answers here:

CSS3 animation with gradients.

You can also transition the position instead, as described here:

CSS3 gradient transition with background-position.

Some more techniques here:

Animating CSS3 Gradients.