:root {
  color-scheme: dark;
  --bg: #0d1117;
  --surface: #161b22;
  --surface-raised: #21262d;
  --border: #30363d;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --accent-blue: #5f9ce1;
  --accent-red: #dd716c;
  --status-loading-bg: #132339;
  --status-loading-text: #58a6ff;
  --status-error-bg: #2d1517;
  --status-error-text: #ff7b72;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html {
  background: var(--bg);
  color-scheme: dark;
}

body {
  font-family: system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  padding: 1.5rem;
  line-height: 1.5;
  min-height: 100vh;
}

header { margin-bottom: 1.5rem; }

.header-top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

h1 { font-size: 1.75rem; font-weight: 700; color: var(--text); }

.range-control {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.range-control select {
  padding: 0.4rem 0.6rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface-raised);
  font-size: 0.9rem;
  color: var(--text);
}

.range-control select:focus {
  outline: 2px solid var(--accent-blue);
  outline-offset: 1px;
}

#subtitle { color: var(--text-muted); margin-top: 0.25rem; font-size: 0.95rem; }

#status {
  margin-top: 0.75rem;
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  font-size: 0.9rem;
  display: none;
}

#status.loading {
  display: block;
  background: var(--status-loading-bg);
  color: var(--status-loading-text);
  border: 1px solid #1f3a5f;
}

#status.error {
  display: block;
  background: var(--status-error-bg);
  color: var(--status-error-text);
  border: 1px solid #5c2124;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.25rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.35);
}

.card h2 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text);
}

.chart-wrap { position: relative; height: 260px; }