style.css

body{
	--size: 16;
	background-color: #2C2F33;
	margin: 0px;
}
h1{
	text-align: center;
	font-family: Optima,Segoe,Segoe UI,Candara;
	font-size: 50px;
	background-color: gray;
	margin: 0px;
	color: white;
	border-bottom: 2px solid black;
	border-radius: 12px;
}
#main{
	display: table;
	margin: 0 auto;
}
#grid{
	display: grid;
	float: left;
	grid-template-columns: repeat(var(--size), 1fr);
	width: 20em;
	height: 20em;
	margin-top: 15px;
	background-color: black;
	border: 2px solid black;
}
#grid > div {
	background-color: rgba(256,256,256,1);
	opacity: 1;
}
#grid div:hover{
	background-color: grey;
}
#colors{
	display: inline-block;
	list-style-type: none;
}
#rainbow{
	background: violet; /* For browsers that do not support gradients */
    background: -webkit-linear-gradient(left, orange , yellow, green, cyan, blue, violet); /* For Safari 5.1 to 6.0 */
    background: -o-linear-gradient(right, orange, yellow, green, cyan, blue, violet); /* For Opera 11.1 to 12.0 */
    background: -moz-linear-gradient(right, orange, yellow, green, cyan, blue, violet); /* For Firefox 3.6 to 15 */
	background: linear-gradient(to right, orange , yellow, green, cyan, blue, violet); 
}
#sketch{
	background: gray;
	background: linear-gradient(to right,white,black);
}
li{
	margin: 15px;
	border-width: medium;
}
.but-active{
	border-color: gold;
}
#options{
	display: table;
	margin: 10px auto;
	padding-right: 100px;
	color: white;
}
#size-input{
	width: 15px;
}
@media only screen and (max-device-width: 768px){
	#grid{
		width: 50em;
		height: 50em;
	}
	#colors > li{
		margin: 40px;
	}
	#colors > li > input{
		height: 50px;
		width: 50px;
	}
	#options > *{
		width: 100px;
		height: 70px;
		font-size: 30px;
		margin: 20px;
	}
}