*, *::before, *::after { box-sizing: border-box }
* { margin: 0; padding: 0 }

html {
	font-family: 'IBM Plex Mono', monospace;;
	font-size: 16px;
	font-weight: 400;
	line-height: 1.5rem;
	font-feature-settings: "kern" on, "liga" on, "calt" off;
	-webkit-text-size-adjust: 100%;

	--figure: #000;
	--ground: #eee;
	--input: #fff;
	--bwidth: 1.5px;
}

body {
	color: var(--figure);
	background-color: var(--ground);
	user-select: none;
	padding: 1rem;
}

a {
	color: inherit;
}

h1 {
	font-size: 1rem;
	text-transform: uppercase;
	letter-spacing: 0.1em;
}


input {
	display: inline-block;
	font: inherit;
	line-height: inherit;
	color: inherit;
	border: none;
	margin: 0;
	width: 100%;
}

input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button { -webkit-appearance: none } /* thanks: https://stackoverflow.com/a/4298216 */
input[type=number] { -moz-appearance: textfield }

input:focus {
	outline: none;
	box-shadow: inset 0 0 0 2px;
}

svg { overflow: visible; }
svg .fill { fill: currentColor; }
svg .stroke {
	stroke: currentColor;
	stroke-width: var(--bwidth);
	fill: none;
	vector-effect: non-scaling-stroke;
}
svg g {
	transform-origin: center;
	transition: all	100ms ease-out;
}

header,
main,
footer {
	width: 100%;
	max-width: 50rem;
	margin: 0 auto;
	min-width: 18rem;
}

header {
	margin: 1rem auto 2rem;
}

main {
	padding-top: 3rem;
	position: relative;
	display: flex;
}

footer {
	color: #999;
	font-size: .8rem;
	padding: 5rem 1rem 1rem 1rem;
}


/* -------------------------------- */

#input,
#steps,
#rows,
#output {
	border: var(--bwidth) solid;
}

#input,
#steps,
#output {
	padding: .25rem .5rem;
}

#input,
#output {
	white-space: nowrap;
	overflow: hidden;
	line-height: 1.5rem;
	height: 3rem;
	margin: 1.5rem 0;
	user-select: all;
}

#input  { background-color: var(--input); }
#output { background-color: transparent; }


/* -------------------------------- */

#controls {
	position: relative;
	width: 12rem;
	height: 12rem;
	flex-basis: 12rem;
	margin-right: 1rem;
}

#text {
	flex-grow: 1;
	position: relative;
}


/* -------------------------------- */

#controls::before,
#text::before,
#text::after {
	content: '';
	display: block;
	position: absolute;
}

#controls::before {
	width: 3rem;
	height: 0;
	border-top: var(--bwidth) solid;
	top: 5.8rem;
	left: 100%;
}

#text::before {
	width: 0;
	height: 3rem;
	border-left: var(--bwidth) solid;
	top: 4.5rem;
	left: 2rem;
}

#text::after {
	width:  .75rem;
	height: .75rem;
	background-color: var(--ground);
	border: var(--bwidth) solid;
	border-radius: 50%;
	top: 5.5rem;
	left: 1.7rem;
}

#steps {
	text-align: center;
	width: 3rem;
	height: 3rem;
	display: block;
	border-radius: 50%;
	position: absolute;
	top: 50%;
	left: 50%;
	margin: -1.5rem;
}