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

:root {
  --bg: #0f172a;
  --card-bg: #1e293b;
  --card-border: #334155;
  --text: #f1f5f9;
  --text-muted: #94a3b8;
  --accent: #38bdf8;
  --max-width: 960px;
}

body {
  margin: 0;
  font-family:
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    Roboto,
    sans-serif;
  font-size: 16px;
  line-height: 1.5;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  padding: 2rem 1rem;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
}

.header {
  margin-bottom: 2.5rem;
  text-align: center;
}

.header h1 {
  margin: 0 0 0.25rem;
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.subtitle {
  margin: 0;
  color: var(--text-muted);
  font-size: 1rem;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
  margin-bottom: 2.5rem;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 1.5rem;
  transition: border-color 0.2s ease;
}

.card:hover {
  border-color: var(--accent);
}

.card h2 {
  margin: 0 0 0.5rem;
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.metric-value {
  margin: 0;
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  color: var(--text);
}

.chart-section {
  margin-bottom: 2.5rem;
}

.chart-section h2 {
  margin: 0 0 1rem;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-muted);
}

.chart-container {
  position: relative;
  width: 100%;
  min-height: 280px;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 1.25rem;
}

.chart-container canvas {
  max-width: 100%;
}

.footer {
  padding-top: 1.5rem;
  border-top: 1px solid var(--card-border);
  text-align: center;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.footer p {
  margin: 0 0 0.5rem;
}

.footer a {
  color: var(--accent);
  text-decoration: none;
}

.footer a:hover {
  text-decoration: underline;
}