:root {
	--paper: #f6f4ef;
	--paper-deep: #eeece5;
	--surface: #fbfaf7;
	--ink: #242620;
	--ink-soft: #686b61;
	--ink-faint: #96998e;
	--line: #deddd4;
	--line-strong: #cbc9bf;
	--vermillion: #ad5142;
	--vermillion-soft: #f3e5df;
	--green: #52685d;
	--green-soft: #e7ede7;
	--radius: 2px;
	--font-sans:
		-apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
		"Microsoft YaHei", sans-serif;
	--font-serif: "Songti SC", "STSong", "SimSun", serif;
}

* {
	box-sizing: border-box;
}

html {
	min-width: 320px;
	background: var(--paper);
	color: var(--ink);
	font-family: var(--font-sans);
	text-rendering: optimizeLegibility;
}

body {
	min-width: 320px;
	min-height: 100svh;
	margin: 0;
	overflow-x: hidden;
	background:
		radial-gradient(
			circle at 50% 8%,
			rgba(255, 255, 255, 0.74),
			transparent 34rem
		),
		var(--paper);
	color: var(--ink);
}

button,
input {
	font: inherit;
}

button {
	cursor: pointer;
}

button:disabled {
	cursor: not-allowed;
}

button:focus-visible,
a:focus-visible,
input:focus-visible {
	outline: 2px solid var(--vermillion);
	outline-offset: 4px;
}

[hidden] {
	display: none !important;
}

.app-shell {
	display: flex;
	flex-direction: column;
	width: min(100%, 980px);
	min-height: 100svh;
	margin: 0 auto;
	padding: 0 clamp(20px, 5vw, 64px);
}

.site-header {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 16px;
	min-height: 72px;
	padding-top: env(safe-area-inset-top);
	border-bottom: 1px solid var(--line);
}

.brand {
	display: inline-flex;
	align-items: center;
	gap: 10px;
	color: var(--ink);
	text-decoration: none;
}

.brand-coin {
	display: block;
	width: 24px;
	height: 24px;
	object-fit: contain;
	flex: 0 0 auto;
}

.brand-name {
	font-family: var(--font-serif);
	font-size: 16px;
	letter-spacing: 0.16em;
}

.brand-note,
.site-footer {
	color: var(--ink-faint);
	font-size: 11px;
	letter-spacing: 0.08em;
}

.brand-note {
	margin: 0;
}

#app-main {
	display: flex;
	flex: 1;
	min-height: 0;
}

.view {
	width: 100%;
	max-width: 680px;
	margin: 0 auto;
}

.home-view {
	display: flex;
	flex-direction: column;
	justify-content: center;
	padding: clamp(54px, 12vh, 128px) 0 56px;
}

.hero-copy {
	max-width: 500px;
}

.eyebrow,
.section-kicker {
	margin: 0;
	color: var(--vermillion);
	font-size: 11px;
	font-weight: 600;
	letter-spacing: 0.17em;
	line-height: 1.5;
}

.hero-copy h1,
.casting-header h1,
.result-hero h1 {
	margin: 18px 0 12px;
	font-family: var(--font-serif);
	font-weight: 400;
	letter-spacing: 0.06em;
}

.hero-copy h1 {
	font-size: clamp(42px, 10vw, 68px);
	line-height: 1.15;
}

.hero-lede,
.casting-lede {
	margin: 0;
	color: var(--ink-soft);
	font-size: 15px;
	line-height: 1.9;
}

.question-form {
	display: grid;
	gap: 10px;
	max-width: 560px;
	margin-top: clamp(48px, 9vh, 86px);
}

.question-form label {
	display: flex;
	align-items: baseline;
	gap: 8px;
	color: var(--ink);
	font-size: 13px;
	font-weight: 600;
}

.label-hint {
	color: var(--ink-faint);
	font-size: 11px;
	font-weight: 400;
}

.question-form input {
	width: 100%;
	min-height: 52px;
	padding: 0 15px;
	border: 1px solid var(--line-strong);
	border-radius: var(--radius);
	background: rgba(255, 255, 255, 0.44);
	color: var(--ink);
	font-size: 15px;
	transition:
		border-color 180ms ease,
		background-color 180ms ease;
}

.question-form input::placeholder {
	color: var(--ink-faint);
}

.question-form input:hover {
	border-color: #aaa99f;
}

.question-form input:focus {
	border-color: var(--green);
	background: var(--surface);
	outline: none;
}

.button {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	min-height: 48px;
	gap: 16px;
	padding: 12px 18px;
	border: 1px solid transparent;
	border-radius: var(--radius);
	font-size: 14px;
	font-weight: 600;
	letter-spacing: 0.04em;
	line-height: 1.35;
	text-align: center;
	transition:
		background-color 180ms ease,
		border-color 180ms ease,
		color 180ms ease,
		transform 180ms ease;
}

.button:hover:not(:disabled) {
	transform: translateY(-1px);
}

.button:active:not(:disabled) {
	transform: translateY(0);
}

.button-primary {
	background: var(--ink);
	color: #fffdf8;
}

.button-primary:hover:not(:disabled) {
	background: #41433b;
}

.button-primary:disabled {
	background: #9b9d95;
	color: #f3f2ed;
}

.button-secondary {
	border-color: var(--line-strong);
	background: transparent;
	color: var(--ink);
}

.button-secondary:hover:not(:disabled) {
	border-color: var(--ink-soft);
	background: rgba(255, 255, 255, 0.38);
}

.button-quiet {
	border-color: transparent;
	background: transparent;
	color: var(--ink-soft);
}

.button-quiet:disabled {
	color: var(--ink-faint);
}

.button-arrow {
	color: #c5cec1;
	font-size: 18px;
	font-weight: 400;
}

.ritual-note {
	display: flex;
	align-items: center;
	gap: 12px;
	margin-top: 34px;
	color: var(--ink-faint);
	font-size: 12px;
}

.ritual-note p {
	margin: 0;
}

.ritual-mark {
	display: grid;
	width: 22px;
	height: 22px;
	place-items: center;
	border: 1px solid var(--line-strong);
	border-radius: 50%;
	color: var(--green);
	font-family: var(--font-serif);
	font-size: 12px;
}

/* Casting */
.casting-view {
	padding: clamp(28px, 5vh, 54px) 0 48px;
}

.casting-header {
	max-width: 570px;
}

.result-topline,
.section-heading {
	display: flex;
	align-items: flex-start;
	justify-content: space-between;
	gap: 20px;
}

.step-count {
	display: flex;
	justify-content: center;
	gap: 7px;
	margin: 0;
	color: var(--ink-faint);
	font-size: 12px;
	letter-spacing: 0.05em;
}

.step-count span:first-child {
	color: var(--ink);
	font-weight: 600;
}

.casting-header h1 {
	margin: 17px 0 10px;
	font-size: clamp(27px, 6vw, 42px);
	line-height: 1.35;
}

.coin-stage {
	display: flex;
	align-items: center;
	justify-content: center;
	gap: clamp(14px, 4.5vw, 30px);
	min-width: 0;
	padding: clamp(28px, 6vh, 52px) 0 16px;
	perspective: 1000px;
	perspective-origin: 50% 45%;
}

/* 一个 .coin 是一枚实体；正反两张图只存在于同一个 3D 内层。 */
.coin {
	position: relative;
	display: block;
	flex: 0 0 auto;
	width: clamp(60px, 18vw, 82px);
	aspect-ratio: 1;
	min-width: 0;
}

.coin-inner {
	position: relative;
	z-index: 1;
	width: 100%;
	height: 100%;
	transform: translate3d(0, 0, 0) rotateX(0deg)
		rotateY(var(--coin-final-rotation, 0deg)) rotateZ(0deg) scale(1);
	transform-style: preserve-3d;
}

.coin::after {
	position: absolute;
	right: 15%;
	bottom: 1%;
	left: 15%;
	z-index: 0;
	height: 7%;
	border-radius: 50%;
	background: rgba(55, 57, 47, 0.12);
	content: "";
	filter: blur(4px);
	opacity: 0.3;
	transform: translateY(5px) scaleX(0.9);
	transition:
		opacity 220ms ease,
		transform 220ms ease;
}

.coin-face {
	position: absolute;
	inset: 0;
	display: block;
	width: 100%;
	height: 100%;
	object-fit: contain;
	backface-visibility: hidden;
	-webkit-backface-visibility: hidden;
}

.coin-front {
	transform: rotateY(0deg) translateZ(0.01px);
}

.coin-back {
	transform: rotateY(180deg) translateZ(0.01px);
}

.coin.is-idle {
	opacity: 0.84;
}

.coin.is-tossing,
.coin.is-front,
.coin.is-back,
.coin.is-settled {
	opacity: 1;
}

.coin.is-settled .coin-inner {
	transform: translate3d(0, 0, 0) rotateX(0deg)
		rotateY(var(--coin-final-rotation, 0deg)) rotateZ(0deg) scale(1);
}

.coin.is-tossing .coin-inner {
	animation-name: coin-toss;
	animation-duration: var(--coin-duration, 1100ms);
	animation-delay: var(--coin-delay, 0ms);
	animation-timing-function: cubic-bezier(0.18, 0.86, 0.25, 1);
	animation-fill-mode: both;
	will-change: transform;
}

.coin.is-tossing::after {
	opacity: 0.18;
	transform: translateY(7px) scaleX(0.82);
}

.casting-line-board .line-row.is-revealed {
	animation: line-reveal 220ms cubic-bezier(0.22, 0.7, 0.2, 1) both;
}

.throw-result {
	min-height: 24px;
	margin: 0 0 14px;
	color: var(--ink-soft);
	font-size: 13px;
	line-height: 1.7;
	text-align: center;
}

.throw-control {
	display: grid;
	justify-items: center;
	gap: 11px;
}

.throw-control .button {
	width: min(100%, 280px);
}

.line-board {
	display: grid;
	gap: 0;
	margin: 0;
	padding: 0;
	list-style: none;
}

.casting-line-board {
	max-width: 560px;
	margin: 30px auto 0;
}

.line-row {
	display: grid;
	grid-template-columns: minmax(54px, 74px) minmax(88px, 1fr) minmax(
			74px,
			100px
		);
	align-items: center;
	min-height: 54px;
	gap: 12px;
	padding: 12px 4px;
	border-bottom: 1px solid var(--line);
	background: transparent;
}

.line-row.is-empty {
	color: var(--ink-faint);
}

.line-position {
	display: inline-flex;
	align-items: center;
	gap: 7px;
	color: var(--ink-soft);
	font-size: 12px;
	white-space: nowrap;
}

.line-identity {
	display: flex;
	align-items: center;
	min-width: 0;
	gap: 14px;
}

.line-name {
	color: var(--ink-soft);
	font-size: 12px;
	white-space: nowrap;
}

.line-placeholder {
	color: var(--ink-faint);
	font-family: var(--font-serif);
	font-size: 13px;
	letter-spacing: 0.16em;
	white-space: nowrap;
}

.line-glyph {
	display: flex;
	flex: 0 1 112px;
	align-items: center;
	justify-content: center;
	width: 112px;
	min-width: 0;
	gap: 10px;
}

.line-segment {
	display: block;
	height: 4px;
	border-radius: 99px;
	background: var(--ink);
}

.line-glyph.is-yang .line-segment {
	width: 100%;
}

.line-glyph.is-yin .line-segment {
	width: calc(50% - 5px);
}

.line-marker {
	justify-self: end;
	color: var(--ink-faint);
	font-size: 12px;
	white-space: nowrap;
}

.line-marker.is-moving {
	color: var(--vermillion);
	font-weight: 600;
}

.line-marker-symbol {
	display: inline-block;
	margin-right: 4px;
	font-family: var(--font-serif);
	font-size: 17px;
	line-height: 0;
	vertical-align: -1px;
}

.casting-line-board .line-row.is-current .line-position {
	color: var(--ink);
	font-weight: 600;
}

.casting-line-board .line-row.is-current .line-position::before {
	width: 5px;
	height: 5px;
	border-radius: 50%;
	background: var(--vermillion);
	content: "";
}

.casting-line-board .line-row.is-current .line-marker {
	color: var(--ink-soft);
}

.casting-actions {
	display: flex;
	justify-content: flex-end;
	max-width: 560px;
	margin: 24px auto 0;
}

.quiet-button {
	min-height: 40px;
	padding: 8px 0;
	border: 0;
	background: transparent;
	color: var(--ink-soft);
	font-size: 13px;
}

.quiet-button:hover {
	color: var(--vermillion);
}

.error-message {
	max-width: 560px;
	margin: 16px auto 0;
	color: var(--vermillion);
	font-size: 13px;
	text-align: center;
}

/* Result */
.result-view {
	padding: clamp(28px, 5vh, 52px) 0 0;
}

.result-topline {
	align-items: center;
}

.result-hero {
	padding: clamp(34px, 6vh, 60px) 0 clamp(32px, 5vh, 48px);
	text-align: center;
}

.hexagram-number {
	margin: 0 0 18px;
	color: var(--vermillion);
	font-size: 12px;
	letter-spacing: 0.15em;
}

.result-hero h1 {
	margin: 0;
	font-size: clamp(40px, 10vw, 64px);
	line-height: 1.2;
}

.hexagram-full {
	margin: 13px 0 0;
	color: var(--ink-soft);
	font-family: var(--font-serif);
	font-size: 17px;
	letter-spacing: 0.12em;
}

.judgment-block {
	max-width: 400px;
	margin: 38px auto 0;
	padding-top: 17px;
	border-top: 1px solid var(--line);
}

.judgment-block p {
	margin: 10px 0 0;
	color: var(--ink);
	font-family: var(--font-serif);
	font-size: 17px;
	line-height: 1.9;
}

.result-section {
	padding: 24px 0 0;
	border-top: 1px solid var(--line);
}

.section-heading {
	align-items: end;
	margin-bottom: 16px;
}

.section-heading h2 {
	margin: 6px 0 0;
	font-family: var(--font-serif);
	font-size: 23px;
	font-weight: 400;
	letter-spacing: 0.08em;
}

.section-heading > p {
	margin: 0;
	color: var(--ink-faint);
	font-size: 11px;
	line-height: 1.75;
	text-align: right;
}

.result-line-board {
	width: min(100%, 360px);
	margin: 0 auto;
}

.result-line-board .line-row {
	grid-template-columns: minmax(42px, 1fr) minmax(0, 250px) minmax(42px, 1fr);
	min-height: 56px;
	padding: 12px 0;
}

.result-line-board .line-position {
	color: var(--ink-soft);
}

.result-line-board .line-identity {
	justify-content: center;
	gap: 12px;
}

.result-line-board .line-glyph {
	flex-basis: 215px;
	width: min(215px, calc(100% - 46px));
}

.result-line-board .line-segment {
	height: 5px;
	border-radius: 0;
}

.result-line-board .line-name {
	font-family: var(--font-serif);
	font-size: 12px;
}

.result-line-board .line-row.is-moving .line-name {
	color: var(--ink);
}

.result-line-board .line-row.is-moving .line-marker {
	color: var(--vermillion);
}

.transformation-layout {
	display: grid;
	grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
	align-items: center;
	max-width: 640px;
	margin: 0 auto 24px;
	gap: clamp(16px, 4vw, 40px);
}

.transformation-node {
	min-width: 0;
	text-align: center;
}

.transformation-node strong {
	display: block;
	margin-top: 10px;
	color: var(--ink);
	font-family: var(--font-serif);
	font-size: clamp(16px, 2vw, 20px);
	font-weight: 400;
	line-height: 1.55;
}

.transformation-node p {
	margin: 4px 0 0;
	color: var(--ink-soft);
	font-family: var(--font-serif);
	font-size: 14px;
	line-height: 1.6;
}

.transformation-bridge {
	display: grid;
	justify-items: center;
	min-width: 76px;
	gap: 6px;
	text-align: center;
}

.change-arrow {
	color: var(--vermillion);
	font-family: var(--font-serif);
	font-size: 25px;
	line-height: 1;
}

.movement-copy strong {
	display: block;
	color: var(--vermillion);
	font-family: var(--font-serif);
	font-size: 14px;
	font-weight: 400;
	line-height: 1.5;
}

.movement-copy p {
	margin: 4px 0 0;
	color: var(--ink-faint);
	font-size: 11px;
	line-height: 1.5;
}

.transformation-layout.is-static {
	display: grid;
	grid-template-columns: minmax(0, 1fr) auto;
	max-width: 430px;
	gap: clamp(20px, 5vw, 48px);
}

.transformation-layout.is-static .transformation-bridge {
	gap: 3px;
}

.transformation-layout.is-static .movement-copy strong {
	color: var(--ink-soft);
	font-family: var(--font-sans);
	font-size: 13px;
	font-weight: 600;
}

.result-actions {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	justify-content: center;
	gap: 10px;
	margin-top: clamp(32px, 5vw, 46px);
}

.result-actions .button-primary,
.result-actions .button-secondary {
	flex: 1 1 170px;
}

.copy-status {
	min-height: 21px;
	margin: 12px 0 max(28px, env(safe-area-inset-bottom));
	color: var(--green);
	font-size: 12px;
	text-align: center;
}

.site-footer {
	display: flex;
	justify-content: center;
	padding: 22px 0 max(22px, env(safe-area-inset-bottom));
	border-top: 1px solid var(--line);
	line-height: 1.6;
}

.noscript-message {
	position: fixed;
	right: 20px;
	bottom: 20px;
	left: 20px;
	padding: 14px;
	border: 1px solid var(--vermillion);
	background: var(--surface);
	color: var(--ink);
	font-size: 14px;
	text-align: center;
}

@keyframes coin-toss {
	0% {
		transform: translate3d(0, 0, 0) rotateX(0deg) rotateY(0deg) rotateZ(0deg)
			scale(1);
	}
	18% {
		transform: translate3d(0, var(--coin-lift), 0) rotateX(var(--coin-tilt-x))
			rotateY(var(--coin-spin-1)) rotateZ(var(--coin-tilt-z)) scale(1.025);
	}
	64% {
		transform: translate3d(0, var(--coin-mid-lift), 0)
			rotateX(var(--coin-tilt-x-mid)) rotateY(var(--coin-spin-2))
			rotateZ(var(--coin-tilt-z-mid)) scale(1.012);
	}
	88% {
		transform: translate3d(0, 2px, 0) rotateX(2deg)
			rotateY(var(--coin-settle-rotation)) rotateZ(-1deg) scale(0.996);
	}
	100% {
		transform: translate3d(0, 0, 0) rotateX(0deg)
			rotateY(var(--coin-final-rotation)) rotateZ(0deg) scale(1);
	}
}

@keyframes line-reveal {
	from {
		opacity: 0;
		transform: translateY(3px);
	}
	to {
		opacity: 1;
		transform: translateY(0);
	}
}

@media (min-width: 560px) {
	.question-form {
		grid-template-columns: minmax(0, 1fr) auto;
		align-items: end;
	}

	.question-form label {
		grid-column: 1 / -1;
	}

	.question-form input {
		min-width: 0;
	}

	.question-form .button {
		min-width: 136px;
	}
}

@media (max-width: 560px) {
	.transformation-layout:not(.is-static) {
		grid-template-columns: 1fr;
		gap: 18px;
	}

	.transformation-layout:not(.is-static) .transformation-bridge {
		display: flex;
		flex-direction: column;
		align-items: center;
		justify-content: center;
		width: fit-content;
		max-width: 100%;
		margin-inline: auto;
		gap: 8px;
		text-align: center;
	}

	.transformation-layout:not(.is-static) .change-arrow {
		display: block;
		margin-inline: auto;
		text-align: center;
		transform: rotate(90deg);
	}

	.transformation-layout:not(.is-static) .movement-copy {
		max-width: 100%;
		text-align: center;
	}

	.transformation-layout.is-static {
		display: flex;
		flex-direction: column;
		gap: 16px;
	}

	.transformation-layout.is-static .transformation-bridge {
		width: fit-content;
		max-width: 100%;
		margin-inline: auto;
	}
}

@media (max-width: 470px) {
	.result-line-board {
		width: min(100%, 340px);
	}

	.result-actions .button-primary,
	.result-actions .button-secondary {
		flex-basis: 0;
		min-width: 0;
	}

	.casting-line-board .line-row {
		grid-template-columns: 45px minmax(78px, 1fr) minmax(64px, 78px);
		gap: 7px;
		padding-inline: 9px;
	}

	.casting-line-board .line-glyph {
		width: 90px;
		flex-basis: 90px;
	}

	.line-name,
	.line-marker {
		font-size: 11px;
	}

	.result-line-board .line-row {
		grid-template-columns: 40px minmax(0, 1fr) 46px;
		gap: 8px;
	}

	.result-line-board .line-identity {
		gap: 10px;
	}

	.result-line-board .line-glyph {
		flex-basis: 190px;
		width: min(190px, calc(100% - 34px));
	}
}

@media (max-width: 390px) {
	.app-shell {
		padding-inline: 16px;
	}

	.brand-note {
		display: none;
	}

	.casting-line-board .line-row {
		grid-template-columns: 42px minmax(72px, 1fr) minmax(59px, 72px);
	}

	.casting-line-board .line-glyph {
		width: 78px;
		flex-basis: 78px;
		gap: 7px;
	}

	.result-line-board .line-row {
		grid-template-columns: 36px minmax(0, 1fr) 42px;
		gap: 7px;
	}

	.result-line-board .line-glyph {
		flex-basis: 174px;
		width: min(174px, calc(100% - 34px));
		gap: 8px;
	}
}

@media (prefers-reduced-motion: reduce) {
	*,
	*::before,
	*::after {
		scroll-behavior: auto !important;
		animation-duration: 1ms !important;
		animation-iteration-count: 1 !important;
		transition-duration: 1ms !important;
	}

	.coin.is-tossing .coin-inner {
		animation: none !important;
		transform: translate3d(0, 0, 0) rotateX(0deg)
			rotateY(var(--coin-final-rotation, 0deg)) rotateZ(0deg) scale(1) !important;
	}
}