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

:root {
	--text: #333333;

	--blue: #55acee;
	--l-blue: #6fc6ff;
	--d-blue: #3c93d5;

	--green: #2ecc71;
	--l-green: #48e68b;
	--ul-green: hsl(145, 100%, 90%);
	--d-green: #15b358;

	--red: #e74c3c;
	--l-red: #ff6656;
	--ul-red: hsl(7, 100%, 90%);
	--d-red: #ce3323;

	--cell-bg: #fffaf0;

	--bg-outer: #d2d2d2;
	--bg-inner: #eeeeee;
}
	
body {
	display: flex;
	justify-content: center;

	height: 100vh;
	background-color: #f0f8ff;
	font-family: Arial, sans-serif;
	text-align: center;

	background-color: var(--bg-outer);
}

main {
	display: flex;
	flex-flow: column nowrap;
	gap: 20px;

	height: 100%;
	padding: 20px;

	justify-content: center;
	align-items: center;

	background-color: var(--bg-inner);

	width: min(100%, 600px);
}

footer {
	height: 125px;
	padding-top: 20px;
}

h1, h2 {
	color: var(--text);
}
h1 {
	/* margin-bottom: 20px; */
}

.board, .choice {
	gap: 10px;
}

.board {
	display: grid;
	grid-template-columns: repeat(3, 1fr);
	grid-template-rows: repeat(3, 1fr);
	/* flex-grow: 1; */

}

.choice {
	display: flex;
	flex-direction: row;
	justify-content: center;
	align-items: center;
}

.cell {
	width: 100px;
	height: 100px;

	background-color: var(--cell-bg);
	border: 3px solid #333333;
	transition: background-color .1s ease;

	display: flex;
	justify-content: center;
	align-items: center;

	font-size: 2em;
	font-weight: bold;

	cursor: pointer;
	user-select: none;
}

.cell:hover {
	background-color: #e0e0e0;
}

.x {
	color: var(--red);
}

.o {
	color: var(--green);
}

a {
	all: unset;
	cursor: pointer;
}

.b {
	font-weight: bold;
}

.btn {
	padding: 15px 25px;
	margin: 20px; /* who tf uses margin? */
	
	border-radius: 5px;

	font-size: 22px;
	text-decoration: none;
	color: #fff;
	transition: background-color .1s ease;
	user-select: none;

	display: inline-block;
}
.btn:active {
	transform: translate(0px, 5px);
	box-shadow: 0px 1px 0px 0px;
}

.blue {
	background-color: var(--blue);
	box-shadow: 0px 5px 0px 0px var(--d-blue);
}
.blue:hover {
	background-color: var(--l-blue);
}

.green {
	background-color: var(--green);
	box-shadow: 0px 5px 0px 0px var(--d-green);
}
.green:hover {
	background-color: var(--l-green);
}

.red {
	background-color: var(--red);
	box-shadow: 0px 5px 0px 0px var(--d-red);
}
.red:hover {
	background-color: var(--l-red);
}

.highlight {
	transition: background-color 1s ease;
}

.highlight.x, .highlight.x:hover {
	background-color: var(--ul-red);
}

.highlight.o, .highlight.o:hover {
	background-color: var(--ul-green);
}

.hidden {
	display: none;
}

.scale {
	transform: scale(0);
	height: 0px;
}

.theme-toggle {
	font-size: 0.75rem;
	text-decoration: underline;
	cursor: pointer;
	user-select: none;
	color: var(--text);

	position: absolute;
	bottom: 40px;

}

@media screen and (max-width: 400px) {

}

.theme-transition :is(body, main, h1, h2, .theme-toggle) {
	transition: background-color 0.3s ease, color 0.3s ease;
}

:root.dark {
	--text: #eeeeee;
	--bg-outer: #2a2a2a;
	--bg-inner: #333333;
	--cell-bg: #444444;

	--ul-green: hsl(145, 50%, 20%);	
	--ul-red: hsl(7, 50%, 20%);
}

.dark .cell {
	border-color: #202020;
}
.dark .cell:hover {
	background-color: #555555;
}