:root {
  --bg: #0f172a;
  --panel: #1e293b;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #0ea5e9;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  padding: 24px;
  max-width: 900px;
  margin-inline: auto;
}

.header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  flex-wrap: wrap;
  gap: 12px;
}

.header h1 { margin: 0; font-size: 1.8rem; }
.subtitle { margin: 4px 0 0; color: var(--muted); }

.current { text-align: right; }
.current .temp { font-size: 2.4rem; font-weight: 700; color: var(--accent); }
.current .as-of { display: block; color: var(--muted); font-size: 0.8rem; }

.ranges {
  display: flex;
  gap: 8px;
  margin: 20px 0;
}

.ranges button {
  background: var(--panel);
  color: var(--text);
  border: 1px solid transparent;
  border-radius: 999px;
  padding: 6px 16px;
  cursor: pointer;
  font-size: 0.9rem;
}

.ranges button.active {
  border-color: var(--accent);
  color: var(--accent);
}

.chart {
  width: 100%;
  height: 420px;
  background: var(--panel);
  border-radius: 12px;
  padding: 8px;
}

.empty { color: var(--muted); text-align: center; padding: 40px; }