How to make a bone shaped button

Question

I am currently experimenting on a button for my website. I want it to look like an average button but, once you hover it, it becomes a bone (my website is about dogs).

So I used an already existing codepen project and I ended up with this:

:root {
    --bg: #1a1e24;
    --color: #eee;
    --font: Montserrat, Roboto, Helvetica, Arial, sans-serif;
}

.wrapper {
    padding: 1.5rem 0;
    filter: url('#goo');
}

.bone {
    display: inline-block;
    text-align: center;
    background: var(--color);
    color: var(--bg);
    font-weight: bold;
    padding: 1em 1em 1.03em;
    line-height: 1;
    border-radius: 0.4em;
    position: relative;
    min-width: 8.23em;
    text-decoration: none;
    font-family: var(--font);
    font-size: 1.25rem;
}

.bone:before,
.bone:after {
    width: 2em;
    height: 2em;
    position: absolute;
    content: "";
    display: inline-block;
    background: var(--color);
    border-radius: 50%;
    transition: transform 1s ease;
    transform: scale(0);
    z-index: -1;
    
}

.bone:before {
    top: 50%;
    right: -10%;
}

.bone:after {
    bottom: 50%;
    right: -10%;
}

.bone:hover:before,
.bone:hover:after {
    transform: none;
}


/* Demo styles */

body {
    width: 100%;
    height: 100%;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: var(--bg)
}

<div class="wrapper">
    <a class="bone" href="#">Woof woof</a>
</div>

<!-- Filter: https://css-tricks.com/gooey-effect/ -->
<svg style="visibility: hidden; position: absolute;" width="0" height="0" xmlns="http://www.w3.org/2000/svg" version="1.1">
    <defs>
        <filter id="goo"><feGaussianBlur in="SourceGraphic" stdDeviation="10" result="blur" />    
            <feColorMatrix in="blur" mode="matrix" values="1 0 0 0 0  0 1 0 0 0  0 0 1 0 0  0 0 0 19 -9" result="goo" />
            <feComposite in="SourceGraphic" in2="goo" operator="atop"/>
        </filter>
    </defs>
</svg>

As you can see, I have been able to create the bone shape on the right side of the button, by using the ::before and ::after elements.

However, now that I want to do the same for the left side, I can't really do it because I have already used the ::before and ::after.

Is there anyway to do the same on the left side of the button?

Answer 1

Let's keep it simple! You can add a span inside your a tag and with that having new pseudo elements available to do the left part of the bone

:root {
  --bg: #1a1e24;
  --color: #eee;
  --font: Montserrat, Roboto, Helvetica, Arial, sans-serif;
}

.bone {
  filter: url('#goo');
  display: inline-block;
  text-align: center;
  background: var(--color);
  color: var(--bg);
  font-weight: bold;
  padding: 1em 1em 1.03em;
  line-height: 1;
  border-radius: 0.4em;
  position: relative;
  min-width: 8.23em;
  text-decoration: none;
  font-family: var(--font);
  font-size: 1.25rem;
}

.bone::before,
.bone::after,
.bone span::before,
.bone span::after {
  content: "";
  width: 2em;
  height: 2em;
  position: absolute;
  display: inline-block;
  background: var(--color);
  border-radius: 50%;
  transition: transform 1s ease;
  transform: scale(0);
  z-index: -1;
}


/*top*/

.bone::before,
.bone span::before {
  top: 50%;
}


/*bottom*/

.bone::after,
.bone span::after {
  bottom: 50%;
}


/*right*/

.bone::before,
.bone::after {
  right: -10%;
}


/*left*/

.bone span::before,
.bone span::after {
  left: -10%;
}

.bone:hover::before,
.bone:hover::after,
.bone:hover span::before,
.bone:hover span::after {
  transform: none;
}


/* Demo styles */

body {
  margin: 0;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: var(--bg)
}

<a class="bone" href="#">
  <span>Woof woof</span>
</a>

<!-- Filter: https://css-tricks.com/gooey-effect/ -->
<svg style="visibility: hidden; position: absolute;" width="0" height="0" xmlns="http://www.w3.org/2000/svg" version="1.1">
    <defs>
        <filter id="goo"><feGaussianBlur in="SourceGraphic" stdDeviation="10" result="blur" />    
            <feColorMatrix in="blur" mode="matrix" values="1 0 0 0 0  0 1 0 0 0  0 0 1 0 0  0 0 0 19 -9" result="goo" />
            <feComposite in="SourceGraphic" in2="goo" operator="atop"/>
        </filter>
    </defs>
</svg>

Answer 2

A different idea of animation with less of code:

:root {
    --bg: #1a1e24;
    --color: #eee;
    --font: Montserrat, Roboto, Helvetica, Arial, sans-serif;
}

.bone {
    display: inline-block;
    text-align: center;
    background: var(--color);
    color: var(--bg);
    font-weight: bold;
    padding: 1em 1em 1.03em;
    line-height: 1;
    border-radius: 0.4em;
    position: relative;
    min-width: 8.23em;
    text-decoration: none;
    font-family: var(--font);
    font-size: 1.25rem;
    filter: url('#goo');
}

.bone:before {
    content: "";
    position: absolute;
    top:-1em;  
    bottom:-1em;
    left:0;
    right:0;
    background: 
      radial-gradient(farthest-side,var(--color) 98%,transparent 100%) top    left,
      radial-gradient(farthest-side,var(--color) 98%,transparent 100%) top    right,
      radial-gradient(farthest-side,var(--color) 98%,transparent 100%) bottom left,
      radial-gradient(farthest-side,var(--color) 98%,transparent 100%) bottom right;
    background-size: 0 0;
    background-repeat:no-repeat;
    transition:0.8s ease-out;
}
.bone:hover::before {
    background-size: 50px 50px;
    left:-1em;
    right:-1em;
}

/* Demo styles */

body {
    min-height: 100vh;
    margin:0;
    display: flex;
    justify-content: center;
    align-items: center;
    background: var(--bg)
}

<a class="bone" href="#">Woof woof</a>


<!-- Filter: https://css-tricks.com/gooey-effect/ -->
<svg style="visibility: hidden; position: absolute;" width="0" height="0" xmlns="http://www.w3.org/2000/svg" version="1.1">
    <defs>
        <filter id="goo"><feGaussianBlur in="SourceGraphic" stdDeviation="10" result="blur" />    
            <feColorMatrix in="blur" mode="matrix" values="1 0 0 0 0  0 1 0 0 0  0 0 1 0 0  0 0 0 19 -9" result="goo" />
            <feComposite in="SourceGraphic" in2="goo" operator="atop"/>
        </filter>
    </defs>
</svg>

You can adjust different values to control the final shape using CSS variables:

.bone {
    --ty:-1em;
    --tx:-1em;
    --s:50px;
    display: inline-block;
    text-align: center;
    background: var(--color);
    color: var(--bg);
    font-weight: bold;
    padding: 1em 1em 1.03em;
    margin:2em;
    line-height: 1;
    border-radius: 0.4em;
    position: relative;
    min-width: 8.23em;
    text-decoration: none;
    font-family:  Montserrat, Roboto, Helvetica, Arial, sans-serif;
    font-size: 1.25rem;
    filter: url('#goo');
}

.bone:before {
    content: "";
    position: absolute;
    top:var(--ty);  
    bottom:var(--ty);
    left:0;
    right:0;
    background: 
      radial-gradient(farthest-side,var(--color) 98%,transparent 100%) top    left,
      radial-gradient(farthest-side,var(--color) 98%,transparent 100%) top    right,
      radial-gradient(farthest-side,var(--color) 98%,transparent 100%) bottom left,
      radial-gradient(farthest-side,var(--color) 98%,transparent 100%) bottom right;
    background-size: 0 0;
    background-repeat:no-repeat;
    transition:0.7s;
}
.bone:hover::before {
    background-size: var(--s) var(--s);
    left:var(--tx);
    right:var(--tx);
}

body {
    background:var(--bg);
    --bg:#1a1e24;
    --color:#eee;
}

<a class="bone" href="#">Woof woof</a>
<a class="bone" href="#" style="--ty:-0.5em;--s:35px;">Woof woof</a>
<a class="bone" href="#" style="--tx:-0.5em;--s:40px;">Woof </a>
<a class="bone" href="#" style="--tx:-1.2em;--ty:-1.3em;--s:55px;">Woof </a>


<!-- Filter: https://css-tricks.com/gooey-effect/ -->
<svg style="visibility: hidden; position: absolute;" width="0" height="0" xmlns="http://www.w3.org/2000/svg" version="1.1">
    <defs>
        <filter id="goo"><feGaussianBlur in="SourceGraphic" stdDeviation="10" result="blur" />    
            <feColorMatrix in="blur" mode="matrix" values="1 0 0 0 0  0 1 0 0 0  0 0 1 0 0  0 0 0 19 -9" result="goo" />
            <feComposite in="SourceGraphic" in2="goo" operator="atop"/>
        </filter>
    </defs>
</svg>

Still another kind of animation:

.bone {
    --ty:-1em;
    --tx:-1em;
    --s:50px;
    display: inline-block;
    text-align: center;
    background: var(--color);
    color: var(--bg);
    font-weight: bold;
    padding: 1em 1em 1.03em;
    margin:2em;
    line-height: 1;
    border-radius: 0.4em;
    position: relative;
    z-index:0;
    min-width: 8.23em;
    text-decoration: none;
    font-family:  Montserrat, Roboto, Helvetica, Arial, sans-serif;
    font-size: 1.25rem;
    filter: url('#goo');
}

.bone:before {
    content: "";
    position: absolute;
    z-index:-1;
    top:50%;  
    bottom:50%;
    left:0;
    right:0;
    background: 
      radial-gradient(farthest-side,var(--color) 98%,transparent 100%) top    left,
      radial-gradient(farthest-side,var(--color) 98%,transparent 100%) top    right,
      radial-gradient(farthest-side,var(--color) 98%,transparent 100%) bottom left,
      radial-gradient(farthest-side,var(--color) 98%,transparent 100%) bottom right;
    background-size: var(--s) var(--s);
    background-repeat:no-repeat;
    transition:0.6s;
}
.bone:hover::before {
    top:var(--ty);  
    bottom:var(--ty);
    left:var(--tx);
    right:var(--tx);
}

body {
    background:var(--bg);
    --bg:#1a1e24;
    --color:#eee;
}

<a class="bone" href="#">Woof woof</a>
<a class="bone" href="#" style="--ty:-0.5em;--s:35px;">Woof woof</a>
<a class="bone" href="#" style="--tx:-0.5em;--s:40px;">Woof </a>
<a class="bone" href="#" style="--tx:-1.2em;--ty:-1.3em;--s:55px;">Woof </a>


<!-- Filter: https://css-tricks.com/gooey-effect/ -->
<svg style="visibility: hidden; position: absolute;" width="0" height="0" xmlns="http://www.w3.org/2000/svg" version="1.1">
    <defs>
        <filter id="goo"><feGaussianBlur in="SourceGraphic" stdDeviation="10" result="blur" />    
            <feColorMatrix in="blur" mode="matrix" values="1 0 0 0 0  0 1 0 0 0  0 0 1 0 0  0 0 0 19 -9" result="goo" />
            <feComposite in="SourceGraphic" in2="goo" operator="atop"/>
        </filter>
    </defs>
</svg>