:root {
	--bg: #F7F7F5;
	--surface: #FFFFFF;
	--surface2: #F4F4F2;
	--border: rgba(0, 0, 0, 0.07);
	--border2: rgba(0, 0, 0, 0.11);
	--ink: #1A1A1A;
	--ink2: #5C5C5C;
	--ink3: #9A9A9A;
	--accent: #5B6AF0;
	--accent-lt: #EEF0FE;
	--accent-dk: #3D4EC8;
	--green: #18A66A;
	--green-lt: #E9FAF3;
	--red: #E5484D;
	--red-lt: #FFF0F0;
	--amber: #C07C10;
	--amber-lt: #FFF8ED;
	--diff: rgba(24, 166, 106, 0.28);
	--radius: 12px;
	--radius-sm: 8px;
	--shadow: 0 1px 3px rgba(0,0,0,0.05), 0 4px 12px rgba(0,0,0,0.04);
}

* { box-sizing: border-box; }

body {
	margin: 0;
	min-height: 100vh;
	font-family: "DM Sans", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
	color: var(--ink);
	background: var(--bg);
	padding: 24px 20px 60px;
}

.app {
	width: min(960px, 100%);
	margin: 0 auto;
	display: grid;
	gap: 16px;
}

/* ── Card ── */
.card {
	background: var(--surface);
	border-radius: var(--radius);
	border: 1px solid var(--border);
	box-shadow: var(--shadow);
	overflow: hidden;
}

.card-header {
	padding: 18px 24px 14px;
	border-bottom: 1px solid var(--border);
}

.card-header h1 {
	margin: 0;
	font-size: 17px;
	font-weight: 700;
	letter-spacing: -0.3px;
	color: var(--ink);
}

.card-header h2 {
	margin: 0;
	font-size: 15px;
	font-weight: 600;
	letter-spacing: -0.2px;
	color: var(--ink);
}

.card-header p {
	margin: 6px 0 0;
	font-size: 13px;
	color: var(--ink3);
	line-height: 1.5;
}

.card-body { padding: 16px 24px 24px; }

/* ── Language switch ── */
.lang-switch {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 10px;
	flex-wrap: wrap;
	margin-bottom: 12px;
}

.lang-switch-label {
	font-size: 13px;
	color: var(--ink2);
}

.lang-options {
	display: inline-flex;
	gap: 4px;
}

.lang-btn {
	appearance: none;
	border: 1px solid var(--border2);
	border-radius: var(--radius-sm);
	padding: 5px 10px;
	font-family: inherit;
	font-size: 12px;
	font-weight: 600;
	color: var(--ink2);
	background: var(--surface);
	cursor: pointer;
	transition: background 0.15s, border-color 0.15s, color 0.15s;
}

.lang-btn:hover { background: var(--surface2); }
.lang-btn.active {
	border-color: var(--accent);
	color: var(--accent);
	background: var(--accent-lt);
}

/* ── Chip cards grid ── */
.grid {
	display: grid;
	gap: 12px;
	grid-template-columns: repeat(2, minmax(0, 1fr));
}

.chip-card {
	border: 1px solid var(--border);
	border-radius: var(--radius-sm);
	background: var(--surface2);
	padding: 14px;
	display: grid;
	gap: 8px;
	cursor: pointer;
	transition: border-color 0.15s, box-shadow 0.15s, background 0.15s;
}

.chip-card input { accent-color: var(--accent); }

.chip-card.active {
	border-color: var(--accent);
	box-shadow: 0 0 0 1px rgba(91, 106, 240, 0.2);
	background: var(--accent-lt);
}

.chip-title {
	display: flex;
	align-items: center;
	gap: 8px;
	font-weight: 600;
	font-size: 14px;
}

.chip-info {
	margin: 0;
	color: var(--ink3);
	font-size: 12px;
	line-height: 1.5;
}

/* ── Form ── */
.form-group {
	display: flex;
	flex-direction: column;
	gap: 5px;
	margin-top: 12px;
}

.form-group label {
	font-size: 12px;
	font-weight: 600;
	text-transform: uppercase;
	letter-spacing: 0.5px;
	color: var(--ink3);
}

input[type="text"] {
	font-family: "DM Mono", "SF Mono", SFMono-Regular, ui-monospace, Menlo, Consolas, monospace;
	font-size: 14px;
	padding: 9px 12px;
	border: 1px solid var(--border2);
	border-radius: var(--radius-sm);
	background: var(--surface);
	color: var(--ink);
	outline: none;
	transition: border-color 0.15s, box-shadow 0.15s;
	width: 100%;
}

input[type="text"]:focus {
	border-color: var(--accent);
	box-shadow: 0 0 0 3px rgba(91, 106, 240, 0.12);
}

/* ── Dropzone ── */
.dropzone {
	display: block;
	border: 2px dashed var(--border2);
	border-radius: var(--radius-sm);
	padding: 22px;
	text-align: center;
	color: var(--ink2);
	background: var(--surface2);
	transition: border-color 0.15s, background 0.15s;
	cursor: pointer;
}

.dropzone input[type="file"] {
	display: none;
}

.dropzone-title {
	display: block;
	font-size: 14px;
	color: var(--ink);
	font-weight: 600;
}

.dropzone-sub {
	display: block;
	margin-top: 6px;
	font-size: 12px;
	color: var(--ink3);
}

.dropzone:hover,
.dropzone.dragover {
	border-color: var(--accent);
	background: var(--accent-lt);
	color: var(--ink);
}

/* ── Buttons ── */
.actions {
	margin-top: 14px;
	display: flex;
	flex-wrap: wrap;
	gap: 8px;
}

.btn {
	appearance: none;
	font-family: inherit;
	font-size: 14px;
	font-weight: 600;
	padding: 10px 20px;
	border-radius: var(--radius-sm);
	border: none;
	cursor: pointer;
	display: inline-flex;
	align-items: center;
	gap: 8px;
	transition: background 0.15s, box-shadow 0.15s, transform 0.1s;
}

.btn:active { transform: scale(0.98); }

.btn-primary {
	color: #fff;
	background: var(--accent);
}

.btn-primary:hover { background: var(--accent-dk); }

.btn-secondary {
	color: var(--ink2);
	background: var(--surface);
	border: 1px solid var(--border2);
}

.btn-secondary:hover { background: var(--surface2); }

.btn[disabled] {
	opacity: 0.45;
	cursor: not-allowed;
	transform: none;
}

/* ── Hint ── */
.hint {
	margin: 10px 0 0;
	font-size: 13px;
	color: var(--ink3);
}

.hint.ok { color: var(--green); }
.hint.warn { color: var(--amber); }
.hint.error { color: var(--red); }

/* ── Compare ── */
.compare-wrap {
	display: grid;
	gap: 12px;
	grid-template-columns: repeat(2, minmax(0, 1fr));
}

.compare-box {
	border: 1px solid var(--border);
	border-radius: var(--radius-sm);
	overflow: hidden;
	min-height: 360px;
	display: grid;
	grid-template-rows: auto 1fr;
	background: var(--surface);
}

.compare-title {
	padding: 8px 12px;
	border-bottom: 1px solid var(--border);
	font-size: 12px;
	font-weight: 600;
	color: var(--ink3);
	text-transform: uppercase;
	letter-spacing: 0.5px;
}

.hex-view {
	margin: 0;
	padding: 12px;
	overflow: auto;
	white-space: pre;
	font: 12px/1.55 "DM Mono", "SF Mono", SFMono-Regular, ui-monospace, Menlo, Consolas, monospace;
	color: var(--ink);
}

.changed {
	background: var(--diff);
	border-radius: 3px;
	padding: 0 1px;
}

/* ── Meta ── */
.meta {
	display: flex;
	flex-wrap: wrap;
	gap: 8px;
	margin-top: 12px;
}

.meta-item {
	font-size: 12px;
	color: var(--ink3);
	background: var(--surface2);
	border-radius: var(--radius-sm);
	border: 1px solid var(--border);
	padding: 5px 10px;
	white-space: nowrap;
}

.meta-item strong {
	color: var(--ink);
	font-weight: 600;
}

@media (max-width: 720px) {
	body { padding: 16px 12px 40px; }
	.card-header { padding: 14px 16px 12px; }
	.card-body { padding: 12px 16px 16px; }
	.grid,
	.compare-wrap {
		grid-template-columns: 1fr;
	}
}