:root{font-family:system-ui,-apple-system,Segoe UI,sans-serif;color-scheme:light dark}body{margin:0;max-width:720px;margin-inline:auto;padding:1rem}nav{display:flex;gap:.5rem;margin-bottom:1.5rem}nav button{padding:.5rem 1rem;border:1px solid #888;background:transparent;border-radius:6px;cursor:pointer}nav button[aria-current=true]{background:#4a7dfc;color:#fff;border-color:#4a7dfc}.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:1rem;margin-bottom:1.5rem}.stat-card{border:1px solid #ccc;border-radius:8px;padding:1rem;text-align:center}.stat-card .value{font-size:1.75rem;font-weight:700}form{display:flex;flex-direction:column;gap:.5rem;margin-bottom:1.5rem}.error{color:#d32f2f}.empty-state{color:#666;font-style:italic}ul.session-list{list-style:none;padding:0}ul.session-list li{display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid #eee;padding:.5rem 0}