:root {
	--paper: #faf8f3;
	--card: #ffffff;
	--ink: #23211d;
	--ink-soft: #6b6862;
	--line: #e6e2d8;
	--wechat: #07c160;
	--alipay: #1677ff;
	--btc: #d97706;
	--radius: 14px;
}

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

body {
	background: var(--paper);
	color: var(--ink);
	font-family: "Space Grotesk", sans-serif;
	min-height: 100vh;
	display: flex;
	flex-direction: column;
	align-items: center;
	padding: 64px 20px 48px;
}

a {
	color: inherit;
}

.mono {
	font-family: "JetBrains Mono", monospace;
	letter-spacing: 0.04em;
}

.eyebrow {
	font-size: 12px;
	letter-spacing: 0.2em;
	color: var(--ink-soft);
	text-transform: uppercase;
	margin-bottom: 18px;
}

.hero {
	text-align: center;
	max-width: 640px;
	margin-bottom: 56px;
}

.hero h1 {
	font-weight: 700;
	font-size: clamp(34px, 6vw, 54px);
	letter-spacing: -0.01em;
	line-height: 1.15;
	margin-bottom: 18px;
}

.hero p {
	color: var(--ink-soft);
	font-size: 17px;
	line-height: 1.75;
}

.cards {
	display: grid;
	grid-template-columns: repeat(3, minmax(0, 1fr));
	gap: 16px;
	max-width: 900px;
	width: 100%;
}

.card {
	background: var(--card);
	border: 1px solid var(--line);
	border-radius: var(--radius);
	padding: 32px 24px;
	cursor: pointer;
	transition:
		transform 0.25s ease,
		box-shadow 0.25s ease,
		border-color 0.25s ease;
	display: flex;
	flex-direction: column;
	align-items: flex-start;
	gap: 12px;
}

.card:hover,
.card:focus-visible {
	transform: translateY(-4px);
	box-shadow: 0 12px 28px rgba(35, 33, 29, 0.08);
}

.card[data-c="wechat"]:hover {
	border-color: var(--wechat);
}

.card[data-c="alipay"]:hover {
	border-color: var(--alipay);
}

.card[data-c="btc"]:hover {
	border-color: var(--btc);
}

.card-dot {
	width: 10px;
	height: 10px;
	border-radius: 50%;
}

.card[data-c="wechat"] .card-dot {
	background: var(--wechat);
}

.card[data-c="alipay"] .card-dot {
	background: var(--alipay);
}

.card[data-c="btc"] .card-dot {
	background: var(--btc);
}

.card-title {
	font-weight: 600;
	font-size: 20px;
}

.card-sub {
	font-size: 12px;
	color: var(--ink-soft);
}

.card-cta {
	margin-top: 8px;
	font-size: 14px;
	color: var(--ink-soft);
	display: flex;
	align-items: center;
	gap: 6px;
}

.card-cta::after {
	content: "→";
	transition: transform 0.25s ease;
}

.card:hover .card-cta::after {
	transform: translateX(4px);
}

/* modal */
.overlay {
	position: fixed;
	inset: 0;
	background: rgba(35, 33, 29, 0.55);
	backdrop-filter: blur(4px);
	display: flex;
	align-items: center;
	justify-content: center;
	opacity: 0;
	pointer-events: none;
	transition: opacity 0.3s ease;
	z-index: 100;
	padding: 20px;
}

.overlay.open {
	opacity: 1;
	pointer-events: auto;
}

.modal {
	background: var(--card);
	border-radius: 20px;
	width: 100%;
	max-width: 420px;
	padding: 32px 28px 28px;
	position: relative;
	transform: scale(0.94) translateY(8px);
	transition: transform 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
	box-shadow: 0 24px 64px rgba(35, 33, 29, 0.25);
	max-height: 90vh;
	overflow-y: auto;
}

.overlay.open .modal {
	transform: scale(1) translateY(0);
}

.modal-close {
	position: absolute;
	top: 16px;
	right: 16px;
	width: 30px;
	height: 30px;
	border-radius: 50%;
	border: none;
	background: var(--paper);
	color: var(--ink-soft);
	font-size: 16px;
	cursor: pointer;
	display: flex;
	align-items: center;
	justify-content: center;
	transition: background 0.2s ease;
}

.modal-close:hover {
	background: var(--line);
}

.modal-head {
	display: flex;
	align-items: center;
	gap: 10px;
	margin-bottom: 20px;
}

.modal-title {
	font-weight: 600;
	font-size: 21px;
}

.modal-sub {
	font-size: 12px;
	color: var(--ink-soft);
}

.qr-wrap {
	border-radius: 12px;
	padding: 16px;
	max-width: 320px;
	margin: 0 auto 16px;
	display: block;
}

#modal-wechat .qr-wrap,
#modal-alipay .qr-wrap {
	background: #fff;
	border: 1px solid var(--line);
}

#modal-btc .qr-wrap {
	background: #fff;
	border: 2px solid var(--btc);
}

.qr-wrap img {
	width: 100%;
	display: block;
	border-radius: 4px;
}

.qr-wrap:hover img {
	opacity: 0.92;
}

.hint {
	text-align: center;
	font-size: 14px;
	color: var(--ink-soft);
	margin-bottom: 4px;
}

.btc-address {
	font-family: "JetBrains Mono", monospace;
	font-size: 12.5px;
	background: var(--paper);
	border: 1px solid var(--line);
	padding: 10px 12px;
	border-radius: 6px;
	word-break: break-all;
	margin: 14px 0 10px;
	line-height: 1.5;
}

.btc-meta {
	font-family: "JetBrains Mono", monospace;
	font-size: 11px;
	color: var(--ink-soft);
	display: flex;
	justify-content: space-between;
	padding: 0 2px 10px;
	border-bottom: 1px dashed var(--line);
	margin-bottom: 4px;
}

.copy-btn {
	display: block;
	width: 100%;
	background: transparent;
	border: 1.5px solid var(--line);
	color: var(--ink);
	font-family: "JetBrains Mono", monospace;
	font-size: 13px;
	padding: 11px;
	border-radius: 8px;
	cursor: pointer;
	transition: all 0.2s ease;
	margin-top: 4px;
}

#modal-wechat .copy-btn:hover,
#modal-wechat .copy-btn.copied {
	border-color: var(--wechat);
}

#modal-alipay .copy-btn:hover,
#modal-alipay .copy-btn.copied {
	border-color: var(--alipay);
}

#modal-btc .copy-btn:hover,
#modal-btc .copy-btn.copied {
	border-color: var(--btc);
}

.copy-btn.copied {
	color: #fff;
}

#modal-wechat .copy-btn.copied {
	background: var(--wechat);
}

#modal-alipay .copy-btn.copied {
	background: var(--alipay);
}

#modal-btc .copy-btn.copied {
	background: var(--btc);
}

.why-section {
	max-width: 600px;
	margin-top: 64px;
	padding-top: 40px;
	border-top: 1px solid var(--line);
	text-align: center;
}

.why-label {
	font-size: 12px;
	letter-spacing: 0.2em;
	color: var(--ink-soft);
	margin-bottom: 16px;
}

.why-body {
	font-size: 16px;
	line-height: 1.85;
	color: var(--ink-soft);
}

.about {
	margin-top: 40px;
	display: flex;
	gap: 20px;
	flex-wrap: wrap;
	justify-content: center;
	font-size: 14px;
}

.about a {
	text-decoration: none;
	color: var(--ink-soft);
	border-bottom: 1px solid var(--line);
	padding-bottom: 2px;
	transition:
		color 0.2s ease,
		border-color 0.2s ease;
}

.about a:hover {
	color: var(--ink);
	border-color: var(--ink);
}

@media (max-width: 720px) {
	body {
		padding: 48px 16px 40px;
	}

	.cards {
		grid-template-columns: 1fr;
	}

	.hero {
		margin-bottom: 40px;
	}

	.why-section {
		margin-top: 48px;
		padding-top: 32px;
	}

	.about {
		gap: 14px 20px;
	}
}