CSS Transition on another class img:hover

Question

I have a class with this :hover effect that gives the image color. And I have this separate class that shows the '+' on :hover, but only when I hover this class. I want to have both :hover effects on one img:hover:

Code for the img:hover effect. (using b/w filter).

.og-grid li > a,
.og-grid li > a img {
    border: none;
    outline: none;
    display: block;
    position: relative;
    -webkit-filter: grayscale(100%); 
    filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'/></filter></svg>#grayscale"); 
}

.og-grid li > a,
.og-grid li > a img:hover{
    -webkit-filter: grayscale(0%);
    filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'1 0 0 0 0, 0 1 0 0 0, 0 0 1 0 0, 0 0 0 1 0\'/></filter></svg>#grayscale");
}

Code for the + hover effect.

.viewmore {
    margin-left: 350px;
    opacity: 0;
    position: absolute;
    z-index: 100;
}

.viewmore:hover{
    opacity: 100;
    margin-top: 45px;
    transition: all ease 0.9s;
}

HTML (want to apply this on all img in the grid) : viewmore.png is the '+' img that fades in when I hover it.

<img src="img/viewmore.png" class="viewmore">
    <ul id="og-grid" class="og-grid">             
        <li>  
            <a href="" data-largesrc="img/work/sunmoon.jpg" data-title="MoonSun Shades" data-description="Swiss chard pumpkin bunya nuts maize plantain aubergine napa cabbage soko coriander sweet pepper water spinach winter purslane shallot tigernut lentil beetroot.">
                <img src="img/work/sunmoon2.jpg" alt="img01"/>
            </a>
        </li>
    </ul>

GIF: https://gyazo.com/fe388835229cf2492a0188f2d29a12df

I want to use see them both at the same time when I hover the img.

Answer 1

The trick is to have the :hover pseudoclass on a parent element. When you hover the parent, you can then move one of the children.

I've reorganised your code a bit and introduced more semantic class names:

.view-more img.main {
    transition: all 1s ease;
    display: block;
    -webkit-filter: grayscale(100%); 
    filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0\'/></filter></svg>#grayscale"); 
}

.view-more:hover img.main {
    -webkit-filter: grayscale(0%);
    filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'><filter id=\'grayscale\'><feColorMatrix type=\'matrix\' values=\'1 0 0 0 0, 0 1 0 0 0, 0 0 1 0 0, 0 0 0 1 0\'/></filter></svg>#grayscale");
}
.view-more {
    position: relative; /* needed for child absolute positioning */
    display: inline-block;
    overflow: hidden;
}
.view-more .button {
    right: 10px;
    top: -80px;
    position: absolute;
    z-index: 100;
    opacity: 0;
    transition: all 1s ease;
    border: 1px red solid;
}
.view-more:hover .button {
    top: 0;
    opacity: 1;
}

<a href="#" class="view-more">
    <img class="main" src="https://via.placeholder.com/350x150" alt="img01" width="200"/>
    <img src="https://via.placeholder.com/50x50" class="button" width="50">
</a>