:root {
	--bg: #f1f5fb;
	--surface: #ffffff;
	--surface-soft: #f8fbff;
	--text: #10213a;
	--muted: #5d6f8a;
	--border: #dbe4f0;
	--primary: #1c63f2;
	--primary-hover: #134fce;
	--ok-bg: #e7f8ee;
	--ok-text: #0d7a3f;
	--warn-bg: #fff4e5;
	--warn-text: #a35f00;
	--bad-bg: #ffe7e8;
	--bad-text: #b1202b;
	--shadow: 0 10px 24px rgba(16, 35, 68, 0.08);
}

@media (prefers-color-scheme: dark) {
	:root {
		--bg: #0a1222;
		--surface: #101b2f;
		--surface-soft: #0f1a2d;
		--text: #e8eefb;
		--muted: #9db0cf;
		--border: #243551;
		--primary: #67a2ff;
		--primary-hover: #4a8efa;
		--ok-bg: #103726;
		--ok-text: #79e0a9;
		--warn-bg: #3f2d12;
		--warn-text: #ffd088;
		--bad-bg: #3f1820;
		--bad-text: #ff9ea4;
		--shadow: 0 14px 28px rgba(0, 0, 0, 0.35);
	}
}

* {
	box-sizing: border-box;
}

html,
body {
	margin: 0;
	padding: 0;
}

body {
	font-family: Inter, Segoe UI, Roboto, Arial, sans-serif;
	color: var(--text);
	background: linear-gradient(180deg, #edf3fc 0%, var(--bg) 32%, var(--bg) 100%);
	min-height: 100vh;
}

@media (prefers-color-scheme: dark) {
	body {
		background: radial-gradient(circle at top, #132645 0%, var(--bg) 48%);
	}
}

.main-header {
	width: min(1180px, 96vw);
	margin: 18px auto 10px;
	padding: 20px 22px;
	background: var(--surface);
	border: 1px solid var(--border);
	border-radius: 14px;
	box-shadow: var(--shadow);
}

.main-header h1 {
	margin: 0;
	font-size: clamp(1.42rem, 2.4vw, 2.05rem);
	letter-spacing: -0.012em;
}

.subtitle {
	margin: 6px 0 0;
	color: var(--muted);
	font-size: 0.92rem;
}

.app-notice {
	padding: 10px 12px;
	border-radius: 10px;
	border: 1px solid color-mix(in srgb, var(--warn-text) 44%, var(--border) 56%);
	background: var(--warn-bg);
	color: var(--warn-text);
	font-size: 0.88rem;
	font-weight: 600;
}

.app-notice--error {
	border-color: color-mix(in srgb, var(--bad-text) 44%, var(--border) 56%);
	background: var(--bad-bg);
	color: var(--bad-text);
}

.app-notice--ok {
	border-color: color-mix(in srgb, var(--ok-text) 44%, var(--border) 56%);
	background: var(--ok-bg);
	color: var(--ok-text);
}

.container {
	width: min(1180px, 96vw);
	margin: 0 auto 18px;
	display: grid;
	gap: 12px;
}

.card {
	background: var(--surface);
	border: 1px solid var(--border);
	border-radius: 14px;
	padding: 15px;
	box-shadow: var(--shadow);
}

.card h2 {
	margin: 0 0 9px;
	font-size: clamp(1.08rem, 1.95vw, 1.28rem);
}

.card p {
	margin: 8px 0;
	color: var(--muted);
	line-height: 1.5;
}

.controls-grid {
	display: grid;
	grid-template-columns: repeat(2, minmax(220px, 1fr));
	gap: 12px;
}

.field-group {
	display: grid;
	gap: 6px;
}

.field-group label {
	font-weight: 600;
	font-size: 0.9rem;
}

.field-group input,
.field-group select {
	width: 100%;
	min-height: 40px;
	border: 1px solid var(--border);
	border-radius: 10px;
	background: var(--surface-soft);
	color: var(--text);
	font-size: 0.96rem;
	padding: 0 12px;
}

.field-group input.is-invalid,
.field-group select.is-invalid {
	border-color: var(--bad-text);
	background: color-mix(in srgb, var(--bad-bg) 52%, var(--surface-soft) 48%);
}

.field-group input:focus,
.field-group select:focus,
.button-primary:focus,
.button-secondary:focus,
summary:focus {
	outline: 2px solid color-mix(in srgb, var(--primary) 58%, #ffffff 42%);
	outline-offset: 1px;
}

.field-group small {
	color: var(--muted);
	font-size: 0.82rem;
}

.p-inline {
	display: grid;
	grid-template-columns: minmax(100px, 180px);
}

.stat-strip {
	margin-top: 12px;
	display: grid;
	grid-template-columns: repeat(4, minmax(120px, 1fr));
	gap: 8px;
}

.stat-item {
	background: var(--surface-soft);
	border: 1px solid var(--border);
	border-radius: 10px;
	padding: 9px 10px;
}

.stat-item span {
	color: var(--muted);
	font-size: 0.8rem;
	display: block;
}

.stat-item strong {
	margin-top: 3px;
	font-size: 1.08rem;
	display: block;
}

.status-row {
	margin-top: 10px;
	display: flex;
	align-items: center;
	gap: 10px;
	flex-wrap: wrap;
}

.badge {
	border-radius: 999px;
	padding: 4px 10px;
	font-size: 0.82rem;
	font-weight: 700;
	border: 1px solid transparent;
}

.badge-ok {
	background: var(--ok-bg);
	color: var(--ok-text);
}

.badge-warn {
	background: var(--warn-bg);
	color: var(--warn-text);
}

.badge-bad {
	background: var(--bad-bg);
	color: var(--bad-text);
}

.status-row p {
	margin: 0;
	font-size: 0.92rem;
}

.validation-msg {
	margin-top: 8px;
	padding: 9px 10px;
	border-radius: 10px;
	border: 1px solid color-mix(in srgb, var(--bad-text) 40%, var(--border) 60%);
	background: var(--bad-bg);
	color: var(--bad-text);
	font-size: 0.88rem;
}

details {
	border-radius: 10px;
}

summary {
	cursor: pointer;
	font-weight: 700;
	font-size: 0.96rem;
	user-select: none;
}

.settings-grid {
	margin-top: 12px;
	display: grid;
	grid-template-columns: repeat(2, minmax(200px, 1fr));
	gap: 8px 14px;
}

.switch-item {
	display: flex;
	align-items: center;
	gap: 8px;
	padding: 8px 10px;
	border: 1px solid var(--border);
	border-radius: 10px;
	background: var(--surface-soft);
	font-size: 0.9rem;
}

.switch-item input {
	accent-color: var(--primary);
	width: 16px;
	height: 16px;
}

.card-head {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 10px;
}

.tiny-loading {
	font-size: 0.83rem;
	color: var(--muted);
	padding: 4px 8px;
	border-radius: 999px;
	background: var(--surface-soft);
	border: 1px solid var(--border);
}

.chart-note {
	margin: 6px 0 10px;
	font-size: 0.9rem;
}

.chart-wrap {
	width: 100%;
	min-height: 392px;
	border: 1px solid color-mix(in srgb, var(--primary) 25%, var(--border) 75%);
	border-radius: 12px;
	background: color-mix(in srgb, var(--surface-soft) 90%, var(--surface) 10%);
	padding: 8px;
}

#binomialChart {
	width: 100%;
	height: 380px;
}

.sr-summary {
	margin-top: 8px;
	font-size: 0.9rem;
}

.calculator-grid {
	display: grid;
	grid-template-columns: 1.5fr 1fr 1fr;
	gap: 10px;
}

.inclusivity {
	grid-column: span 3;
	grid-template-columns: 1fr 1fr;
}

.button-primary,
.button-secondary {
	border: 1px solid var(--border);
	border-radius: 10px;
	min-height: 40px;
	padding: 0 14px;
	font-weight: 700;
	cursor: pointer;
	transition: background-color .18s ease, border-color .18s ease, transform .12s ease;
}

.button-primary {
	margin-top: 10px;
	background: var(--primary);
	border-color: var(--primary);
	color: #ffffff;
}

.button-primary:hover {
	background: var(--primary-hover);
}

.button-secondary {
	background: var(--surface-soft);
	color: var(--text);
}

.button-secondary:hover {
	background: color-mix(in srgb, var(--surface-soft) 74%, var(--primary) 26%);
}

.button-primary:active,
.button-secondary:active {
	transform: translateY(1px);
}

.calc-results {
	margin-top: 12px;
	display: grid;
	grid-template-columns: repeat(4, minmax(140px, 1fr));
	gap: 8px;
}

.result-item {
	background: var(--surface-soft);
	border: 1px solid var(--border);
	border-radius: 10px;
	padding: 9px 10px;
}

.result-item span {
	display: block;
	color: var(--muted);
	font-size: 0.8rem;
}

.result-item strong {
	display: block;
	margin-top: 4px;
	font-size: 1.03rem;
}

.calc-extra {
	margin-top: 9px;
	padding: 10px;
	border-radius: 10px;
	border: 1px dashed var(--border);
	background: color-mix(in srgb, var(--surface-soft) 92%, var(--primary) 8%);
}

.calc-extra p {
	margin: 6px 0;
	font-size: 0.9rem;
}

.table-actions {
	display: flex;
	gap: 8px;
	flex-wrap: wrap;
}

.table-wrap {
	margin-top: 8px;
	border: 1px solid var(--border);
	border-radius: 12px;
	max-height: 420px;
	overflow: auto;
	background: var(--surface-soft);
}

table {
	width: 100%;
	border-collapse: collapse;
	min-width: 620px;
}

th,
td {
	border-bottom: 1px solid var(--border);
	text-align: right;
	padding: 8px 10px;
	font-variant-numeric: tabular-nums;
}

th {
	position: sticky;
	top: 0;
	z-index: 1;
	background: color-mix(in srgb, var(--surface-soft) 86%, var(--primary) 14%);
	color: var(--text);
}

td:first-child,
th:first-child {
	text-align: center;
}

tbody tr:hover {
	background: color-mix(in srgb, var(--surface-soft) 68%, var(--primary) 32%);
}

tbody tr.row-expected {
	background: color-mix(in srgb, var(--ok-bg) 66%, var(--surface-soft) 34%);
}

tbody tr.row-sigma-1 {
	box-shadow: inset 3px 0 0 0 #2f9eff;
}

tbody tr.row-sigma-2 {
	box-shadow: inset 3px 0 0 0 #7dbfff;
}

.main-footer {
	width: min(1180px, 96vw);
	margin: 0 auto 22px;
	text-align: center;
	color: var(--muted);
	font-size: 0.88rem;
}

.visually-hidden {
	position: absolute;
	width: 1px;
	height: 1px;
	padding: 0;
	margin: -1px;
	overflow: hidden;
	clip: rect(0, 0, 0, 0);
	white-space: nowrap;
	border: 0;
}

.examples-row {
	margin-top: 10px;
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	gap: 8px;
}

.examples-label {
	font-size: 0.8rem;
	font-weight: 700;
	letter-spacing: 0.04em;
	text-transform: uppercase;
	color: var(--muted);
}

.preset-chip {
	min-height: 34px;
	padding: 0 12px;
	border-radius: 999px;
	border: 1px solid var(--border);
	background: var(--surface-soft);
	color: var(--text);
	font-weight: 600;
	cursor: pointer;
	transition: border-color .16s ease, background-color .16s ease, transform .12s ease;
}

.preset-chip:hover {
	background: color-mix(in srgb, var(--surface-soft) 72%, var(--primary) 28%);
}

.preset-chip.is-active {
	border-color: color-mix(in srgb, var(--primary) 68%, var(--border) 32%);
	background: color-mix(in srgb, var(--primary) 16%, var(--surface-soft) 84%);
	color: color-mix(in srgb, var(--text) 70%, var(--primary) 30%);
}

.preset-chip:active {
	transform: translateY(1px);
}

.card-head-right {
	display: inline-flex;
	align-items: center;
	gap: 8px;
}

.settings-fab {
	width: 34px;
	height: 34px;
	border-radius: 999px;
	border: 1px solid var(--border);
	background: var(--surface-soft);
	color: var(--text);
	font-size: 1rem;
	cursor: pointer;
}

.settings-fab:hover {
	background: color-mix(in srgb, var(--surface-soft) 70%, var(--primary) 30%);
}

.settings-overlay {
	position: fixed;
	inset: 0;
	background: rgba(5, 10, 20, 0.58);
	backdrop-filter: blur(2px);
	z-index: 80;
}

.settings-drawer {
	position: fixed;
	top: 0;
	right: 0;
	width: min(460px, 96vw);
	height: 100vh;
	background: var(--surface);
	border-left: 1px solid color-mix(in srgb, var(--primary) 22%, var(--border) 78%);
	box-shadow: -20px 0 40px rgba(0, 0, 0, 0.3);
	z-index: 90;
	display: grid;
	grid-template-rows: auto 1fr;
	transition: width .2s ease;
}

.drawer-head {
	position: sticky;
	top: 0;
	z-index: 2;
	padding: 12px 14px;
	border-bottom: 1px solid color-mix(in srgb, var(--primary) 20%, var(--border) 80%);
	background: color-mix(in srgb, var(--surface) 92%, var(--surface-soft) 8%);
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 10px;
}

.drawer-head h2 {
	margin: 0;
	font-size: 1.03rem;
}

.drawer-close {
	width: 34px;
	height: 34px;
	border-radius: 999px;
	border: 1px solid var(--border);
	background: var(--surface-soft);
	color: var(--text);
	cursor: pointer;
}

.drawer-controls {
	display: inline-flex;
	align-items: center;
	gap: 0;
}

.drawer-minimize {
	width: 34px;
	height: 34px;
	border-radius: 999px;
	border: 1px solid var(--border);
	background: var(--surface-soft);
	color: var(--text);
	cursor: pointer;
	font-size: 1rem;
	line-height: 1;
}

.drawer-minimize:hover {
	background: color-mix(in srgb, var(--surface-soft) 74%, var(--primary) 26%);
}

.drawer-mini-label {
	display: none;
}

.drawer-body {
	overflow: auto;
	padding: 12px;
	display: grid;
	gap: 10px;
	background: color-mix(in srgb, var(--surface) 88%, var(--surface-soft) 12%);
}

.drawer-group {
	margin: 0;
	padding: 10px;
	border: 1px solid var(--border);
	border-radius: 12px;
	background: var(--surface-soft);
	display: grid;
	gap: 6px;
}

.drawer-group legend {
	padding: 0 5px;
	font-size: 0.8rem;
	font-weight: 700;
	letter-spacing: 0.04em;
	text-transform: uppercase;
	color: var(--muted);
}

.drawer-group .switch-item {
	padding: 8px 10px;
	border: 1px solid color-mix(in srgb, var(--primary) 16%, var(--border) 84%);
	background: color-mix(in srgb, var(--surface-soft) 86%, var(--surface) 14%);
	border-radius: 10px;
}

.drawer-table {
	border: 1px solid var(--border);
	border-radius: 12px;
	padding: 10px;
	background: var(--surface-soft);
}

.drawer-table h3 {
	margin: 0;
	font-size: 0.98rem;
}

.settings-drawer.is-minimized {
	width: 58px;
}

.settings-drawer.is-minimized .drawer-head h2,
.settings-drawer.is-minimized .drawer-body {
	display: none;
}

.settings-drawer.is-minimized .drawer-head {
	justify-content: center;
	padding: 8px;
	border-bottom: 0;
	background: transparent;
}

.settings-drawer.is-minimized .drawer-controls {
	flex-direction: column;
	gap: 6px;
}

.settings-drawer.is-minimized .drawer-mini-label {
	display: block;
	position: absolute;
	top: 52%;
	left: 50%;
	transform: translate(-50%, -50%) rotate(-90deg);
	font-size: 0.74rem;
	letter-spacing: 0.08em;
	text-transform: uppercase;
	color: var(--muted);
	pointer-events: none;
}

.solve-hint {
	margin-top: 0;
	font-size: 0.9rem;
}

.calc-msg {
	margin-top: 10px;
}

.calc-actions {
	margin-top: 10px;
	display: flex;
	gap: 8px;
	flex-wrap: wrap;
}

.button-primary {
	margin-top: 0;
}

.guide-card summary {
	cursor: pointer;
	font-weight: 700;
}

.guide-content {
	padding-top: 4px;
}

.guide-card p {
	font-size: 0.9rem;
	line-height: 1.45;
}

.site-footer {
	width: min(1180px, 96vw);
	margin: 16px auto 22px;
	padding: 10px 12px;
	border: 1px solid var(--border);
	border-radius: 12px;
	background: var(--surface);
	box-shadow: var(--shadow);
}

.footer-container {
	display: grid;
	gap: 8px;
	justify-items: center;
	text-align: center;
}

.footer-nav {
	display: flex;
	flex-wrap: wrap;
	justify-content: center;
	gap: 8px 14px;
}

.footer-link {
	color: var(--muted);
	text-decoration: none;
	font-size: 0.86rem;
}

.footer-link:hover {
	color: var(--primary);
	text-decoration: underline;
}

.copyright-text {
	color: var(--muted);
	font-size: 0.85rem;
}

@media (max-width: 980px) {
	.controls-grid,
	.calculator-grid {
		grid-template-columns: 1fr;
	}

	.stat-strip,
	.calc-results {
		grid-template-columns: repeat(2, minmax(140px, 1fr));
	}

	.inclusivity {
		grid-column: auto;
		grid-template-columns: 1fr;
	}

	#binomialChart {
		height: 300px;
	}
}

@media (max-width: 600px) {
	.main-header,
	.card {
		border-radius: 12px;
		padding: 12px;
	}

	.stat-strip,
	.calc-results {
		grid-template-columns: 1fr;
	}

	.table-actions {
		width: 100%;
	}

	.table-actions .button-secondary {
		flex: 1;
	}

	.calc-actions .button-primary,
	.calc-actions .button-secondary {
		flex: 1;
	}

	#binomialChart {
		height: 260px;
	}

	.chart-wrap {
		min-height: 280px;
	}
}