:root {
  --bg: #f6f7f5;
  --panel: #ffffff;
  --text: #1d2321;
  --muted: #69726e;
  --line: #e3e6e2;
  --grid: #eceeeb;
  --good: #2fa36b;
  --fair: #86b33a;
  --moderate: #d99a1e;
  --poor: #dd6230;
  --bad: #c2384a;
  --c-co2: #148a8a;
  --c-pm25: #8a63e0;
  --c-pm10: #3f2a8c;
  --c-temp: #e0612b;
  --c-hum: #2d7fd3;
  --c-voc: #a2499c;
  --c-nox: #8a6a3b;
  --c-press: #5a6f86;
  --radius: 14px;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121514;
    --panel: #1b1f1e;
    --text: #e6eae8;
    --muted: #8e9894;
    --line: #2b302e;
    --grid: #252a28;
    --c-co2: #3cc4c0;
    --c-pm25: #a088ee;
    --c-pm10: #5e45b5;
    --c-temp: #f08050;
    --c-hum: #5aa5ee;
    --c-voc: #d27ccb;
    --c-nox: #c49a5c;
    --c-press: #8aa0b8;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}

header.top, main, footer {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 16px;
}

header.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-top: 28px;
  padding-bottom: 20px;
}

h1 { margin: 0; font-size: 1.7rem; letter-spacing: -0.01em; }
.sub { margin: 2px 0 0; color: var(--muted); font-size: 0.92rem; }

.pill {
  flex: none;
  padding: 8px 16px;
  border-radius: 999px;
  color: #fff;
  font-weight: 600;
  font-size: 0.95rem;
  background: var(--muted);
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 12px;
}

.card {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px 16px 14px 20px;
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 5px;
  background: var(--lvl, var(--line));
}

.card .k { color: var(--muted); font-size: 0.85rem; }
.card .v { font-size: 1.9rem; font-weight: 650; font-variant-numeric: tabular-nums; line-height: 1.15; margin-top: 2px; }
.card .u { font-size: 0.9rem; font-weight: 500; color: var(--muted); margin-left: 3px; }
.card .l { font-size: 0.82rem; font-weight: 600; color: var(--lvl, var(--muted)); margin-top: 2px; min-height: 1.2em; }

.ranges {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 28px 0 14px;
}

.ranges button {
  font: inherit;
  font-size: 0.9rem;
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--text);
  cursor: pointer;
}

.ranges button.on { background: var(--text); color: var(--bg); border-color: var(--text); }

.charts { display: grid; gap: 14px; }

.chart {
  margin: 0;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px 10px 6px 6px;
  min-width: 0;
}

.chart figcaption { font-weight: 600; padding: 0 8px 6px 10px; }
.chart .hint { font-weight: 400; color: var(--muted); font-size: 0.85rem; margin-left: 6px; }
.chart .plot { width: 100%; min-height: 240px; }
.chart .empty { color: var(--muted); padding: 60px 10px; text-align: center; }

.u-legend { font-size: 0.85rem; color: var(--text); }
.u-legend .u-marker { border-radius: 3px; }
.u-select { background: rgba(127, 127, 127, 0.15); }

footer { color: var(--muted); font-size: 0.85rem; padding-top: 24px; padding-bottom: 40px; }

@media (max-width: 520px) {
  h1 { font-size: 1.4rem; }
  .cards { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
  .card .v { font-size: 1.6rem; }
  .pill { padding: 6px 12px; font-size: 0.85rem; }
}