How to animate concave rectangle to convex

Question

I have created a rectangle of the following shape using sketch.

When I hover it I need to animate and rest as the below shape.

Is there a way I can animate it using css only from concave to convex.

Any help would be appreciated. I am fine with svg solution as well.

Here is the link to the fiddle for svg.

  <svg width="641px" height="313px" viewBox="0 0 641 313" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> <!-- Generator: Sketch 52.5 (67469) - http://www.bohemiancoding.com/sketch --> <title>Concave</title> <desc>Created with Sketch.</desc> <defs> <path d="M0,252.683363 C104.477953,274.894454 210.133596,286 316.966929,286 C423.800262,286 531.811286,274.894454 641,252.683363 L641,565 L0,565 L0,252.683363 Z" id="path-1"></path> </defs> <g id="Page-1" stroke="none" stroke-width="1" fill="none" fill-rule="evenodd"> <g id="iteration-3" transform="translate(-752.000000, -3299.000000)"> <g id="case--study" transform="translate(0.000000, 2766.000000)"> <g transform="translate(50.000000, 100.000000)" id="case--study--1-copy"> <g transform="translate(702.000000, 181.000000)"> <use id="bottom" fill="#000000" fill-rule="nonzero" xlink:href="#path-1"></use> </g> </g> </g> </g> </g> </svg> 

Answer 1

For a CSS only solution I would consider a radial-gradient and some background animation:

 .box { height:50px; width:600px; padding-top:50px; background: /*concave*/ radial-gradient(410px 50px at 50% 0,transparent, 80%, #000 80.5%) center, /*convexe*/ radial-gradient(410px 50px at 50% 50px,#000, 80%, transparent 80.5%)center, linear-gradient(#000,#000) content-box; background-size:100% 100%,100% 0px,auto; background-repeat:no-repeat; transition:1s all; } .box:hover { background-size:100% 0,100% 100%,auto; } 

 <div class="box"></div> 

You can also have it for a full width rectangle:

 .box { height:50px; padding-top:50px; background: /*concave*/ radial-gradient(70% 50px at 50% 0,transparent, 80%, #000 80.5%) center, /*convexe*/ radial-gradient(70% 50px at 50% 50px,#000, 80%, transparent 80.5%)center, linear-gradient(#000,#000) content-box; background-size:100% 100%,100% 0px,auto; background-repeat:no-repeat; transition:1s all; } .box:hover { background-size:100% 0,100% 100%,auto; } 

 <div class="box"></div> 

In case you will have a bigger height or dynamic height better consider a pseudo element so the effect won't get affected by height changing:

 .box { height: 80vh; position: relative; padding-top: 50px; background: #000 content-box; } .box::before { content: ""; position: absolute; top: 1px; left: 0; right: 0; padding: inherit; background: /*concave*/ radial-gradient(70% 50px at 50% 0, transparent, 80%, #000 80.5%) bottom, /*convexe*/ radial-gradient(70% 50px at 50% 50px, #000, 80%, transparent 80.5%)bottom; background-size: 100% 100%, 100% 0px; background-repeat: no-repeat; transition: 1s all; } .box:hover::before { background-size: 100% 0, 100% 100%; } 

 <div class="box"></div> 

Update

You can also adjust the effect like below:

 .box { height: 80vh; position: relative; padding-top: 100px; background: #000 content-box; } /*concave*/ .box::before { content: ""; position: absolute; top: 50px; left: 0; right: 0; height: 51px; background: radial-gradient(70% 50px at 50% 0, transparent, 80%, #000 80.5%) top center; background-size: 100% 200%; background-repeat: no-repeat; transition: 0.5s all 0.4s ease-out; } /*convexe*/ .box::after { content: ""; position: absolute; top: 1px; left: 0; right: 0; height: 51px; background: radial-gradient(70% 50px at 50% 50px, #000, 80%, transparent 80.5%)bottom center; background-size: 200% 0%; background-repeat: no-repeat; transition: 0.5s all ease-in; } .box:hover::before { background-position: bottom center; background-size: 200% 200%; transition: 0.5s all ease-in; } .box:hover::after { background-size: 100% 100%; transition: 0.5s all 0.4s ease-out; } 

 <div class="box"></div> 

Answer 2

One solution could be to create the shape with SVG and then transition the path via CSS:

 body { width: 40vw; display: block; margin: 0 auto; } .path { transition: d 2s ease-in-out; } .path:hover{ d: path('M0 20 Q 50 0 100 20 L100 60 L0 60 Z'); } 

 <svg viewBox="0 0 100 60" xmlns="http://www.w3.org/2000/svg"> <path class="path" d="M0 20 Q 50 40 100 20 L100 60 L0 60 Z" fill="black"/> </svg> <p>hover over the shape</p>