squiggly link

<style>
:root {
		--mainColor: #000;
	}

	a {
		background: linear-gradient(to bottom, var(--mainColor) 0%, var(--mainColor) 100%);
		background-position: 0 95%;
		background-repeat: repeat-x;
		background-size: 5px 5px;
		text-decoration: none;
        }

	a:hover {
		background-image: url("data:image/svg+xml;charset=utf8,%3Csvg id='squiggle-link' xmlns='http://www.w3.org/2000/svg' xmlns:xlink='http://www.w3.org/1999/xlink' xmlns:ev='http://www.w3.org/2001/xml-events' viewBox='0 0 20 4'%3E%3Cstyle type='text/css'%3E.squiggle{animation:shift .3s linear infinite;}@keyframes shift {from {transform:translateX(0);}to {transform:translateX(-20px);}}%3C/style%3E%3Cpath fill='none' stroke='%23000' stroke-width='3' class='squiggle' d='M0,3.5 c 5,0,5,-3,10,-3 s 5,3,10,3 c 5,0,5,-3,10,-3 s 5,3,10,3'/%3E%3C/svg%3E");
		background-position: 0 115%;
		background-size: 1em .5em;
		background-repeat: repeat-x;
		text-decoration: none;
        }
</style>