/* UK House Prices — design system and layout.
 *
 * Every colour is a token on :root, overridden under prefers-color-scheme:dark.
 * The map and chart read these same tokens at runtime (see js/map.js and
 * js/chart.js) rather than hardcoding values, so the whole interface — the
 * choropleth included — follows the visitor's own browser setting. */

@font-face {
	font-family: 'Inter';
	src: url('../vendor/fonts/inter-var.woff2') format('woff2');
	font-weight: 100 900;
	font-style: normal;
	font-display: swap;
}

:root {
	color-scheme: light;

	--bg: #f5f7f9;
	--surface: #ffffff;
	--surface-sunken: #f8fafc;
	--border: #e5e8ee;
	--border-strong: #d4dae3;

	--text: #0d1117;
	--text-muted: #596273;
	--text-subtle: #868e9d;

	--accent: #1e3a8a;
	--accent-bright: #2563eb;
	--focus-ring: rgba(37, 99, 235, 0.22);

	--pos: #0f766e;
	--neg: #be123c;

	/* Consumed by js/map.js */
	--map-water: #e4eaf1;
	--map-line: rgba(255, 255, 255, 0.6);
	--map-nodata: #dde2e9;
	--ramp-neg: #be123c;
	--ramp-mid: #f8fafc;
	--ramp-pos: #0f766e;

	/* Chart series, in housing-type order */
	--series-0: #0d1117;
	--series-1: #0f766e;
	--series-2: #b45309;
	--series-3: #7c3aed;
	--series-4: #2563eb;

	--r-sm: 6px;
	--r-md: 10px;
	--r-lg: 14px;

	--shadow-sm: 0 1px 2px rgba(13, 17, 23, 0.04);
	--shadow-md: 0 1px 3px rgba(13, 17, 23, 0.06), 0 8px 24px -12px rgba(13, 17, 23, 0.12);

	--topbar-h: 60px;
}

@media (prefers-color-scheme: dark) {
	:root {
		color-scheme: dark;

		--bg: #0a0c10;
		--surface: #12151c;
		--surface-sunken: #171b24;
		--border: #222834;
		--border-strong: #2e3542;

		--text: #e7eaf0;
		--text-muted: #99a2b1;
		--text-subtle: #6e7788;

		--accent: #3b82f6;
		--accent-bright: #60a5fa;
		--focus-ring: rgba(96, 165, 250, 0.25);

		--pos: #2dd4bf;
		--neg: #fb7185;

		--map-water: #0c1017;
		--map-line: rgba(0, 0, 0, 0.4);
		--map-nodata: #1b212b;
		--ramp-neg: #e11d48;
		--ramp-mid: #272e3a;
		--ramp-pos: #14b8a6;

		--series-0: #e7eaf0;
		--series-1: #2dd4bf;
		--series-2: #fbbf24;
		--series-3: #a78bfa;
		--series-4: #60a5fa;

		--shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
		--shadow-md: 0 1px 3px rgba(0, 0, 0, 0.5), 0 8px 24px -12px rgba(0, 0, 0, 0.7);
	}
}

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

html { -webkit-text-size-adjust: 100%; }

body {
	margin: 0;
	font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
	font-size: 14px;
	line-height: 1.55;
	color: var(--text);
	background: var(--bg);
	-webkit-font-smoothing: antialiased;
	-moz-osx-font-smoothing: grayscale;
	font-feature-settings: 'cv05' 1, 'ss01' 1;
}

.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;
}

/* ---------- Top bar ---------- */

.topbar {
	position: sticky;
	top: 0;
	z-index: 20;
	height: var(--topbar-h);
	background: color-mix(in srgb, var(--surface) 82%, transparent);
	backdrop-filter: saturate(180%) blur(12px);
	-webkit-backdrop-filter: saturate(180%) blur(12px);
	border-bottom: 1px solid var(--border);
}

.topbar-inner {
	max-width: 1680px;
	height: 100%;
	margin: 0 auto;
	padding: 0 20px;
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 16px;
}

.brand { display: flex; align-items: center; gap: 11px; min-width: 0; }

.brand-mark {
	display: grid;
	place-items: center;
	width: 32px;
	height: 32px;
	flex: none;
	border-radius: 9px;
	background: var(--accent);
	color: #fff;
}

.brand-mark svg { width: 17px; height: 17px; }

.brand-text { display: flex; flex-direction: column; min-width: 0; }

.brand-name {
	font-size: 14.5px;
	font-weight: 600;
	letter-spacing: -0.017em;
	line-height: 1.25;
}

.brand-sub {
	font-size: 12px;
	color: var(--text-subtle);
	line-height: 1.3;
	white-space: nowrap;
	overflow: hidden;
	text-overflow: ellipsis;
}

.topbar-meta {
	font-size: 12px;
	color: var(--text-subtle);
	white-space: nowrap;
	font-variant-numeric: tabular-nums;
}

@media (max-width: 560px) {
	.brand-sub, .topbar-meta { display: none; }
}

/* ---------- Layout ---------- */

.layout {
	display: grid;
	gap: 16px;
	padding: 16px 20px 28px;
	max-width: 1680px;
	margin: 0 auto;
	grid-template-columns: minmax(0, 1fr);
	grid-template-areas: "controls" "map" "area";
}

@media (min-width: 1024px) {
	.layout {
		grid-template-columns: minmax(340px, 4.2fr) minmax(0, 7.8fr);
		grid-template-areas:
			"controls map"
			"area     map";
		align-items: start;
	}
}

.controls   { grid-area: controls; container: controls / inline-size; }
.map-panel  { grid-area: map; }
.area-panel { grid-area: area; }

.panel {
	background: var(--surface);
	border: 1px solid var(--border);
	border-radius: var(--r-lg);
	box-shadow: var(--shadow-sm);
	padding: 18px;
}

.panel-title {
	margin: 0;
	font-size: 12px;
	font-weight: 600;
	letter-spacing: 0.04em;
	text-transform: uppercase;
	color: var(--text-subtle);
}

.intro {
	margin: 10px 0 18px;
	color: var(--text-muted);
	font-size: 13px;
	line-height: 1.6;
}

/* ---------- Fields ---------- */

.field { margin-bottom: 16px; }
.field:last-child { margin-bottom: 0; }

.field-head {
	display: flex;
	align-items: baseline;
	justify-content: space-between;
	gap: 12px;
	margin-bottom: 8px;
}

.field-row {
	display: grid;
	gap: 12px;
	grid-template-columns: minmax(0, 1fr);
	margin-bottom: 0;
}

/* Keyed to the panel, not the viewport: the controls column stays narrow on
   wide screens, so a viewport query would wrongly place these side by side */
@container controls (min-width: 520px) {
	.field-row { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
}

.field-row .field { margin-bottom: 0; }

label {
	display: block;
	font-size: 12px;
	font-weight: 500;
	color: var(--text-muted);
	margin-bottom: 6px;
}

.field-head label { margin-bottom: 0; }

.range-readout {
	font-size: 13px;
	font-weight: 600;
	font-variant-numeric: tabular-nums;
	color: var(--text);
	white-space: nowrap;
}

.range-arrow { color: var(--text-subtle); font-weight: 400; margin: 0 2px; }

/* ---------- Select ---------- */

.select-wrap { position: relative; }

.select-wrap::after {
	content: '';
	position: absolute;
	right: 12px;
	top: 50%;
	width: 7px;
	height: 7px;
	margin-top: -5px;
	border-right: 1.6px solid var(--text-subtle);
	border-bottom: 1.6px solid var(--text-subtle);
	transform: rotate(45deg);
	pointer-events: none;
}

select {
	appearance: none;
	-webkit-appearance: none;
	width: 100%;
	font: inherit;
	font-size: 13.5px;
	padding: 9px 34px 9px 11px;
	border: 1px solid var(--border-strong);
	border-radius: var(--r-md);
	background: var(--surface);
	color: var(--text);
	cursor: pointer;
	transition: border-color 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

select:hover { border-color: var(--text-subtle); }

select:focus-visible {
	outline: none;
	border-color: var(--accent-bright);
	box-shadow: 0 0 0 3px var(--focus-ring);
}

/* ---------- Dual range slider ---------- */

.range { position: relative; height: 28px; }

.range-track {
	position: absolute;
	left: 0; right: 0;
	top: 50%;
	height: 4px;
	margin-top: -2px;
	border-radius: 999px;
	background: var(--border-strong);
}

.range-fill {
	position: absolute;
	top: 0;
	height: 100%;
	border-radius: 999px;
	background: var(--accent-bright);
}

.range input[type="range"] {
	position: absolute;
	left: 0;
	top: 0;
	width: 100%;
	height: 28px;
	margin: 0;
	background: none;
	appearance: none;
	-webkit-appearance: none;
	pointer-events: none;   /* only the thumbs are interactive */
}

.range input[type="range"]::-webkit-slider-thumb {
	-webkit-appearance: none;
	pointer-events: auto;
	width: 16px;
	height: 16px;
	border-radius: 50%;
	background: var(--surface);
	border: 2px solid var(--accent-bright);
	box-shadow: var(--shadow-sm);
	cursor: grab;
	transition: transform 0.12s ease, box-shadow 0.12s ease;
}

.range input[type="range"]::-moz-range-thumb {
	pointer-events: auto;
	width: 16px;
	height: 16px;
	border-radius: 50%;
	background: var(--surface);
	border: 2px solid var(--accent-bright);
	box-shadow: var(--shadow-sm);
	cursor: grab;
}

.range input[type="range"]:hover::-webkit-slider-thumb { transform: scale(1.12); }
.range input[type="range"]:active::-webkit-slider-thumb { cursor: grabbing; transform: scale(1.05); }

.range input[type="range"]:focus-visible::-webkit-slider-thumb {
	box-shadow: 0 0 0 4px var(--focus-ring);
}

.range input[type="range"]:focus-visible::-moz-range-thumb {
	box-shadow: 0 0 0 4px var(--focus-ring);
}

.range input[type="range"]::-moz-range-track { background: none; }

/* ---------- Map ---------- */

.map-panel { position: relative; padding: 0; overflow: hidden; }

#map {
	width: 100%;
	height: clamp(400px, 62vh, 860px);
	background: var(--map-water);
}

@media (min-width: 1024px) {
	.map-panel { position: sticky; top: calc(var(--topbar-h) + 16px); }
	#map { height: calc(100vh - var(--topbar-h) - 32px); min-height: 560px; }
}

.map-status {
	position: absolute;
	inset: 0;
	display: flex;
	align-items: center;
	justify-content: center;
	gap: 10px;
	background: var(--map-water);
	color: var(--text-muted);
	font-size: 13px;
	pointer-events: none;
}

.map-status[hidden] { display: none; }

.spinner {
	width: 15px;
	height: 15px;
	border: 2px solid var(--border-strong);
	border-top-color: var(--accent-bright);
	border-radius: 50%;
	animation: spin 0.7s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

@media (prefers-reduced-motion: reduce) {
	.spinner { animation-duration: 2s; }
}

/* MapLibre's own controls, restyled to match */
.maplibregl-ctrl-group {
	background: var(--surface) !important;
	border: 1px solid var(--border) !important;
	border-radius: var(--r-md) !important;
	box-shadow: var(--shadow-sm) !important;
	overflow: hidden;
}

.maplibregl-ctrl-group button + button { border-top: 1px solid var(--border) !important; }

/* MapLibre draws its +/- icons as dark SVGs, so invert them on a dark panel */
.maplibregl-ctrl-group button span { filter: var(--ctrl-icon-filter, none); }

@media (prefers-color-scheme: dark) {
	:root { --ctrl-icon-filter: invert(1) brightness(1.6); }
}

.legend {
	position: absolute;
	left: 14px;
	bottom: 14px;
	display: flex;
	flex-direction: column;
	gap: 7px;
	padding: 10px 12px;
	background: color-mix(in srgb, var(--surface) 88%, transparent);
	backdrop-filter: blur(10px);
	-webkit-backdrop-filter: blur(10px);
	border: 1px solid var(--border);
	border-radius: var(--r-md);
	box-shadow: var(--shadow-md);
	font-size: 11px;
	color: var(--text-muted);
	font-variant-numeric: tabular-nums;
}

.legend-scale { display: flex; align-items: center; gap: 8px; }

.legend-ramp {
	width: 124px;
	height: 8px;
	border-radius: 999px;
	background: linear-gradient(to right, var(--ramp-neg), var(--ramp-mid), var(--ramp-pos));
	border: 1px solid var(--border);
}

.legend-label { font-weight: 500; color: var(--text); }

.legend-nodata { display: flex; align-items: center; gap: 6px; font-size: 10.5px; color: var(--text-subtle); }

.legend-swatch {
	width: 10px; height: 10px;
	border-radius: 3px;
	background: var(--map-nodata);
	border: 1px solid var(--border);
}

.map-tooltip {
	position: absolute;
	z-index: 5;
	pointer-events: none;
	padding: 7px 10px;
	background: var(--text);
	color: var(--surface);
	border-radius: var(--r-sm);
	font-size: 12px;
	line-height: 1.4;
	white-space: nowrap;
	box-shadow: var(--shadow-md);
	transform: translate(-50%, -145%);
	opacity: 0;
	transition: opacity 0.12s ease;
}

.map-tooltip.is-visible { opacity: 1; }
.map-tooltip b { font-weight: 600; }
.map-tooltip .tip-value { font-variant-numeric: tabular-nums; opacity: 0.85; }

/* ---------- Area detail ---------- */

.area-head {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 12px;
	margin-bottom: 14px;
	flex-wrap: wrap;
}

.area-select-wrap { flex: 1 1 200px; min-width: 0; }
.area-select-wrap select { font-weight: 550; }

.headline {
	padding: 14px 16px;
	border-radius: var(--r-md);
	background: var(--surface-sunken);
	border: 1px solid var(--border);
	margin-bottom: 16px;
}

.headline-value {
	font-size: 30px;
	font-weight: 650;
	letter-spacing: -0.03em;
	line-height: 1.1;
	font-variant-numeric: tabular-nums;
}

.headline-value.up { color: var(--pos); }
.headline-value.down { color: var(--neg); }

/* An empty reading is a statement, not a number — size it like one */
.headline-value.none {
	color: var(--text-subtle);
	font-size: 17px;
	font-weight: 550;
	letter-spacing: -0.01em;
}

.headline-label {
	margin-top: 3px;
	font-size: 12px;
	color: var(--text-muted);
}

.stats-wrap { overflow-x: auto; margin-bottom: 18px; }

.stats {
	width: 100%;
	border-collapse: collapse;
	font-size: 13px;
	font-variant-numeric: tabular-nums;
}

.stats th, .stats td {
	padding: 8px 10px;
	text-align: right;
	border-bottom: 1px solid var(--border);
	white-space: nowrap;
}

.stats th:first-child, .stats td:first-child { text-align: left; padding-left: 0; }
.stats th:last-child, .stats td:last-child { padding-right: 0; }

.stats thead th {
	font-size: 11px;
	font-weight: 500;
	color: var(--text-subtle);
	padding-bottom: 6px;
}

.stats tbody tr:last-child td { border-bottom: none; }
.stats tbody tr { transition: background 0.12s ease; }
.stats tbody td:first-child { color: var(--text-muted); }
.stats .up { color: var(--pos); font-weight: 550; }
.stats .down { color: var(--neg); font-weight: 550; }
.stats .none { color: var(--text-subtle); }

.chart-block {
	border-top: 1px solid var(--border);
	padding-top: 14px;
}

.chart-title {
	margin: 0 0 10px;
	font-size: 12.5px;
	font-weight: 550;
	color: var(--text-muted);
	text-align: center;
}

#chart { min-height: 250px; }

/* uPlot, toned down to match the panel */
.u-legend { font-size: 11.5px; color: var(--text-muted); margin-top: 6px; }
.u-legend .u-marker { border-radius: 2px; }
.u-select { background: var(--focus-ring); }

/* ---------- Footer ---------- */

.site-footer {
	border-top: 1px solid var(--border);
	background: var(--surface);
}

.footer-inner {
	max-width: 900px;
	margin: 0 auto;
	padding: 12px 20px 16px;
	font-size: 11px;
	line-height: 1.5;
	color: var(--text-subtle);
	text-align: center;
	text-wrap: balance;
}

.footer-inner p { margin: 0; }
.footer-note { color: var(--text-muted); font-weight: 500; margin-bottom: 2px !important; }
.site-footer a { color: var(--accent-bright); text-decoration: none; }
.site-footer a:hover { text-decoration: underline; }