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).

S

Answer 1

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)
}

Woof woof

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;
}

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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;
}

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