:root{--bg: #0f1117;--fg: #e6e8ee;--muted: #8b93a7;--accent: #5da9ff;--card: #181b24;--border: #232838;--err: #ff6b6b;font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--fg);min-height:100vh}.app{max-width:960px;margin:0 auto;padding:32px 24px}header h1{margin:0;font-size:28px;letter-spacing:-.02em}.subtitle{color:var(--muted);margin:4px 0 24px}.card{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:20px 24px}.card h2{margin-top:0;font-size:18px;color:var(--accent)}.err{color:var(--err)}code,pre{background:#0a0c12;border-radius:6px;padding:2px 6px;font-family:ui-monospace,SF Mono,Consolas,monospace;font-size:13px}pre{padding:12px;overflow-x:auto}