:root {
	--margin-btn-letter: 15px;
	--size-btn: 50px;
	--width-logo: 500px;
	--color-background-anti: #333;
	--color-background: #fff;
	--color-box-letter: hsl(44, 28%, 85%);
	--color-btn-letter: hsl(44, 50%, 85%);
	--color-shadow-off: rgba(0, 0, 0, 0);
	--color-shadow-on: rgba(0, 0, 0, 0.35);
	--color-main-1: hsl(37, 3%, 49%);
	--color-main-2: hsl(0, 0%, 50%);
}

[data-theme="dark"] {
	--color-background-anti: #fff;
	--color-background: #333;
	--color-box-letter: hsl(223, 19%, 64%);
	--color-btn-letter: hsl(224, 500%, 85%);
	--color-shadow-off: rgba(255, 255, 255, 0);
	--color-shadow-on: rgba(255, 255, 255, .35);
	--color-main-1: hsl(44, 50%, 85%);
	--color-main-2: hsl(0, 0%, 70%);
}
body {
	overflow: hidden;
	margin: 0;
	user-select: none;
}

.start-overlay {
	position: absolute;
	top: 0;
	height: 100vh;
	width: 100vw;
	z-index: 1000;
	background-color: black;
}

.start-overlay-hidden {
	animation: hideStartOverlay 1s ease-in 0s 1 normal forwards;
}

.start-overlay canvas {
	opacity: inherit;
	height: auto;
	width: 100%;
	max-width: 800px;
	position: absolute;
	top: 0;
	bottom: 0;
	left: 0;
	right: 0;
	margin: auto;
}

.body {
	position: absolute;
	top: 0;
	height: 100vh;
	width: 100vw;
	overflow-x: hidden;
	overflow-y: auto;
	background-color: var(--color-background);
	text-align: center;
}

header .logo {
	margin: 10px auto;
	width: var(--width-logo);
	max-width: 90vw;
}

.box-letter {
	background-color: var(--color-background);
	left: 2vw;
	overflow: hidden;
	position: absolute;
	text-align: center;
	top: 2vh;
	width: 96vw;
	z-index: 50;
}

.box-letter-displayed {
	animation: showBoxLetter .2s cubic-bezier(0.65, 0.05, 0.36, 1) 0s 1 normal both;
}
.box-letter-next-in {
	animation: rightInBoxLetter .2s cubic-bezier(0.65, 0.05, 0.36, 1) 0s 1 normal both;
}
.box-letter-previous-in {
	animation: leftInBoxLetter .2s cubic-bezier(0.65, 0.05, 0.36, 1) 0s 1 normal both;
}

.box-letter-hidden {
	animation: hideBoxLetter .2s cubic-bezier(0.65, 0.05, 0.36, 1) 0s 1 normal both;
}
.box-letter-next-out {
	animation: leftOutBoxLetter .2s cubic-bezier(0.65, 0.05, 0.36, 1) 0s 1 normal both;
}
.box-letter-previous-out {
	animation: rightOutBoxLetter .2s cubic-bezier(0.65, 0.05, 0.36, 1) 0s 1 normal both;
}

.btn-letter-container {
	max-width: 1000px;
	margin: 40px auto;
}

.btn-letter {
	color: var(--color-background-anti);
	border: 4px solid var(--color-background-anti);
	cursor: pointer;
	display: inline-block;
	font-family: "PT Mono", monospace;
	font-size: 10vh;
	height: 25vh;
	line-height: 25vh;
	margin: var(--margin-btn-letter);
	text-align: center;
	vertical-align: middle;
	width: 25vh;
	z-index: 0;
}
.btn-letter:hover {
	animation: shadow-drop-center 0.4s cubic-bezier(0.250, 0.460, 0.450, 0.940) both;
}

.overlay {
	background-color: #000;
	left: 0;
	position: fixed;
	top: 0;
	width: 100vw;
}

.overlay-enabled {
	animation: hide-background .5s ease 0s 1 normal both;
	height: 100vh;
	z-index: 40;
}

.overlay-disabled {
	animation: show-background .5s ease 0s 1 normal both;
}

.next-btn,
.previous-btn {
	position: fixed;
	z-index: 500;
	border-radius: 50%;
	cursor: pointer;
	display: none;
}
.next-enabled {
	animation: nextEnabled 1s ease 0s 1 normal both;
	display: initial;
}
.previous-enabled {
	animation: previousEnabled 1s ease 0s 1 normal both;
	display: initial;
}

.writing-lines-container {
	position: absolute;
	bottom: 60%;
	width: 100%;
	height: 20%;
}

.writing-line {
	position: absolute;
	background-color: var(--color-main-1);
	opacity: 20%;
	width: 0;
	left: 0;
	z-index: 65;
}

.writing-line:first-of-type {
	height: .7em;
	top: 13%;
}

.writing-line:nth-of-type(2) {
	height: .5em;
	opacity: 10%;
	top: 38%;
}

.writing-line:nth-of-type(3) {
	height: 1em;
	top: 100%;
}

.box-letter-displayed .writing-line,
.box-letter-previous-in .writing-line,
.box-letter-next-in .writing-line {
	animation: make-line .5s ease-in-out 0s 1 normal both;
}

.box-letter-hidden .writing-line,
.box-letter-previous-out .writing-line,
.box-letter-next-out .writing-line {
	animation: remove-line .5s ease-in-out;
}

.letters-container {
	position: absolute;
	font-family: 'PT Mono', monospace;
	margin: 0 2.5vh;
	color: var(--color-background-anti);
	width: 100%;
	font-size: 21vh;
	letter-spacing: 5vh;
	text-shadow: .4vh .7vh 0px var(--color-main-2);
	z-index: 100;
}

.box-letter-displayed .pronunciation,
.box-letter-next-in .pronunciation,
.box-letter-previous-in .pronunciation,
.box-letter-displayed .pronunciation-language,
.box-letter-next-in .pronunciation-language,
.box-letter-previous-in .pronunciation-language {
	animation: fade-in .5s;
	display: block;
}
.box-letter-hidden .pronunciation,
.box-letter-next-out .pronunciation,
.box-letter-previous-out .pronunciation,
.box-letter-hidden .pronunciation-language,
.box-letter-next-out .pronunciation-language,
.box-letter-previous-out .pronunciation-language {
	animation: fade-out .5s;
	display: none;
}

.pronunciation {
	font-family: 'Open Sans', sans-serif;
	color: var(--color-main-1);
	opacity: 80%;
	font-size: 8vh;
	position: absolute;
	width: 100%;
	top: 50%;
	display: none;
}

.pronunciation::before,
.pronunciation::after {
	content: '/';
	font-size: 9vh;
}

.pronunciation-language {
	font-family: 'Open Sans', sans-serif;
	text-transform: uppercase;
	letter-spacing: .5vh;
	font-size: 2.5vh;
	display: none;
	position: absolute;
	bottom: 30px;
	left: 0;
	right: 0;
	margin: auto;
}
.pronunciation-language span {
	color: transparent;
	background-clip: text;
	-webkit-background-clip: text;
}



.theme-btn {
	cursor: pointer;
	position: fixed;
	left: 10px;
	top: 10px;
	height: 30px;
	width: 30px;
	border-radius: 50%;
	z-index: 20;

}

@media(hover: none) {
	.theme-btn:hover,
	.previous-enabled:hover,
	.next-enabled:hover {
		opacity: .75;
	}
}

@media(hover: hover) {
	.theme-btn:hover {
		border: 1px solid #888;
	}

	.previous-enabled:hover,
	.next-enabled:hover {
		box-shadow: 0px 0px 2px 1px var(--color-shadow-on);
	}
}