:root {
  --bg: #0a0a0a;
  --fg: #f5f5f5;
  --muted: #cccccc;
  --card: #151515;
  --border: #222222;
  --accent: #00bfa5;
}
* { box-sizing: border-box; }
body {
  margin: 0; padding: 0;
  background: var(--bg); color: var(--fg);
  font-family: system-ui, -apple-system, Segoe UI, Inter, Roboto, Arial, sans-serif;
}
header {
  background: #111; padding: 2rem; text-align: center; border-bottom: 1px solid var(--border);
}
h1 { margin: 0 0 .3rem 0; font-weight: 700; }
h2, h3 { color: var(--muted); margin-top: 0; }
nav { margin-top: 1rem; display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }
nav a { color: var(--accent); text-decoration: none; font-weight: 600; }
nav a:hover { text-decoration: underline; }
section { max-width: 900px; margin: 3rem auto; padding: 0 1.25rem; }
footer { text-align: center; padding: 2rem; border-top: 1px solid var(--border); color: #888; }
.highlight { color: var(--accent); }
.project-card { background: var(--card); border: 1px solid var(--border); padding: 1.25rem; border-radius: 12px; margin-bottom: 1.25rem; }
.container { max-width: 1000px; margin: 2rem auto; padding: 0 1.25rem; }
.chart { background: var(--card); border: 1px solid var(--border); border-radius: 12px; padding: 1rem; margin: 1rem 0; }
iframe { width: 100%; border: 1px solid var(--border); border-radius: 12px; }
.btn {
  display:inline-block; padding:.7rem 1rem; border:1px solid var(--border); border-radius:10px;
  color: var(--fg); background:#121212; text-decoration:none; font-weight:600;
}
.btn:hover { border-color: var(--accent); color: var(--accent); }
.small { color:#aaa; font-size:.9rem; }
.chart { min-height: 420px; }
.chart.sankey { min-height: 560px; }