:root {
	--bg-top: #11204a;
	--bg-bottom: #fdf1b8;
	--panel: rgba(255, 255, 255, 0.86);
	--panel-strong: rgba(255, 255, 255, 0.93);
	--ink: #22304f;
	--muted: #576784;
	--accent: #ff7d66;
	--sun: #ffd45e;
	--shadow: 0 22px 55px rgba(25, 40, 75, 0.18);
}

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

body {
	margin: 0;
	min-height: 100vh;
	min-height: 100dvh;
	font-family: 'Nunito', sans-serif;
	color: var(--ink);
	background:
		radial-gradient(circle at 14% 18%, rgba(255, 212, 94, 0.95), rgba(255, 212, 94, 0) 16%),
		radial-gradient(circle at 84% 14%, rgba(255, 255, 255, 0.28), rgba(255, 255, 255, 0) 17%),
		linear-gradient(180deg, var(--bg-top) 0%, #3357a1 42%, #7ad9ff 70%, var(--bg-bottom) 100%);
}

button,
a {
	font: inherit;
}

.app-shell {
	max-width: 1180px;
	margin: 0 auto;
	padding: clamp(0.85rem, 2vw, 1.4rem);
	display: grid;
	gap: 0.75rem;
}

.hero-card,
.music-card,
.piano-card {
	background: var(--panel);
	border: 1px solid rgba(255, 255, 255, 0.75);
	box-shadow: var(--shadow);
	backdrop-filter: blur(12px);
	border-radius: 2rem;
	padding: clamp(1rem, 2vw, 1.4rem);
}

.hero-card {
	display: flex;
	justify-content: space-between;
	align-items: center;
	gap: 1rem;
	background: linear-gradient(135deg, rgba(255, 255, 255, 0.94), rgba(255, 245, 214, 0.94));
}

.eyebrow {
	margin: 0 0 0.35rem;
	text-transform: uppercase;
	letter-spacing: 0.16em;
	font-size: 0.76rem;
	font-weight: 900;
	color: #5d73a9;
}

h1,
h2,
p {
	margin: 0;
}

h1 {
	font-family: 'Fredoka', 'Nunito', sans-serif;
	font-size: clamp(2rem, 4vw, 3.4rem);
	line-height: 0.98;
	margin-bottom: 0.5rem;
}

h2 {
	font-family: 'Fredoka', 'Nunito', sans-serif;
	font-size: clamp(1.35rem, 2vw, 1.8rem);
	margin-bottom: 0.4rem;
}

.subtitle,
.music-copy p,
.piano-copy p,
#musicText {
	color: var(--muted);
	line-height: 1.45;
}

.page-version {
	margin-top: 0.45rem;
	display: inline-flex;
	padding: 0.28rem 0.6rem;
	border-radius: 999px;
	background: rgba(35, 57, 111, 0.1);
	font-size: 0.78rem;
	font-weight: 800;
	color: #3558a8;
}

#goBack,
.music-button,
.piano-key {
	border: none;
	cursor: pointer;
	transition: transform 0.15s ease, box-shadow 0.15s ease, background-color 0.15s ease;
}

#goBack {
	flex: 0 0 auto;
	text-decoration: none;
	color: white;
	font-weight: 900;
	padding: 0.85rem 1.1rem;
	border-radius: 999px;
	border: 2px solid rgba(255, 255, 255, 0.4);
	background: linear-gradient(180deg, #ff6b6b 0%, #e03131 100%);
	box-shadow: 0 12px 28px rgba(224, 49, 49, 0.32);
	text-shadow: 0 1px 0 rgba(0, 0, 0, 0.16);
}

#goBack:hover,
#goBack:focus-visible,
.music-button:hover,
.music-button:focus-visible,
.piano-key:hover,
.piano-key:focus-visible {
	transform: translateY(-2px);
	outline: none;
}

#goBack:hover,
#goBack:focus-visible {
	box-shadow: 0 16px 32px rgba(224, 49, 49, 0.38);
	outline: 3px solid rgba(255, 107, 107, 0.3);
	outline-offset: 2px;
}

.music-card,
.piano-card {
	display: grid;
	grid-template-columns: minmax(210px, 280px) minmax(0, 1fr);
	gap: 0.8rem;
	align-items: start;
}

.piano-card {
	padding: clamp(0.85rem, 1.8vw, 1.15rem);
}

.music-buttons {
	display: grid;
	grid-template-columns: repeat(auto-fit, minmax(110px, 1fr));
	gap: 0.55rem;
}

.music-button {
	padding: 0.7rem 0.7rem;
	border-radius: 1rem;
	background: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(239, 244, 255, 0.94));
	box-shadow: 0 8px 18px rgba(53, 88, 168, 0.12);
	text-align: left;
	min-height: 64px;
}

.music-button strong,
.music-button span {
	display: block;
}

.music-button strong {
	font-size: 0.88rem;
	color: var(--ink);
	margin-bottom: 0.08rem;
}

.music-button span {
	font-size: 0.72rem;
	color: var(--muted);
	line-height: 1.2;
}

.music-button.is-active {
	background: linear-gradient(180deg, #ffd56d, #ffbf52);
	box-shadow: 0 16px 28px rgba(255, 172, 57, 0.28);
}

.music-button.is-stop {
	background: linear-gradient(180deg, rgba(242, 245, 252, 0.98), rgba(226, 233, 247, 0.94));
}

.music-status {
	margin-top: 0.45rem;
	font-size: 0.84rem;
	font-weight: 800;
}

.piano {
	display: grid;
	grid-template-columns: repeat(8, minmax(0, 1fr));
	gap: 0.55rem;
	padding: 0.55rem;
	background: linear-gradient(180deg, rgba(255, 255, 255, 0.48), rgba(255, 255, 255, 0.18));
	border-radius: 1.35rem;
	box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.8);
	min-height: 260px;
}

.piano-key {
	position: relative;
	display: flex;
	flex-direction: column;
	justify-content: flex-end;
	align-items: center;
	gap: 0.35rem;
	padding: 0.75rem 0.4rem 0.85rem;
	border-radius: 0 0 1.2rem 1.2rem;
	background: linear-gradient(180deg, #fffefb, #f2f4f8 62%, #dfe4ee 100%);
	box-shadow: 0 14px 26px rgba(70, 89, 130, 0.14), inset 0 -14px 20px rgba(100, 115, 145, 0.12), inset 0 2px 0 rgba(255, 255, 255, 0.92);
	min-height: 100%;
	overflow: hidden;
}

.piano-key::before {
	content: '';
	position: absolute;
	inset: 0;
	background: linear-gradient(180deg, transparent, rgba(255, 211, 87, 0.28));
	opacity: 0;
	transition: opacity 0.15s ease;
}

.piano-key.is-active {
	transform: translateY(6px) scale(0.99);
	box-shadow: 0 8px 16px rgba(70, 89, 130, 0.15), inset 0 -8px 12px rgba(100, 115, 145, 0.16);
}

.piano-key.is-active::before {
	opacity: 1;
}

.key-note,
.key-label {
	position: relative;
	z-index: 1;
	font-weight: 900;
	text-align: center;
}

.key-note {
	font-size: clamp(0.98rem, 1.7vw, 1.18rem);
	color: #22304f;
}

.key-label {
	font-size: 0.72rem;
	color: #607090;
	text-transform: uppercase;
	letter-spacing: 0.08em;
}

@media (max-width: 900px) {
	.music-card,
	.piano-card,
	.hero-card {
		grid-template-columns: 1fr;
		display: grid;
	}

	.hero-card {
		justify-content: stretch;
	}

	#goBack {
		justify-self: start;
	}
}

@media (max-width: 680px) {
	.app-shell {
		padding: 0.55rem;
	}

	.hero-card,
	.music-card,
	.piano-card {
		border-radius: 1.3rem;
		padding: 0.85rem;
	}

	.music-buttons {
		grid-template-columns: repeat(3, minmax(0, 1fr));
	}

	.piano {
		grid-template-columns: repeat(4, minmax(0, 1fr));
		min-height: auto;
	}

	.piano-key {
		min-height: 132px;
	}

	#goBack {
		width: 100%;
		justify-self: stretch;
		text-align: center;
	}

@media (max-width: 460px) {
	.music-buttons {
		grid-template-columns: repeat(2, minmax(0, 1fr));
	}

	.piano-key {
		min-height: 124px;
	}
}

@media (prefers-reduced-motion: reduce) {
	*,
	*::before,
	*::after {
		animation: none !important;
		transition: none !important;
	}
}