:root{--bg:#0f1220;--panel:#171a2b;--accent:#5b8cff;--muted:#aab}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:#eee;font:14px/1.5 Inter,system-ui,-apple-system,Segoe UI,Roboto,Arial}.app{display:flex;height:100vh;gap:12px;padding:12px}.pane{flex:1;background:var(--panel);border:1px solid #22283e;border-radius:8px;display:flex;flex-direction:column}.pane h3{margin:0;padding:8px 12px;border-bottom:1px solid #22283e;color:#cfd6ff}textarea,pre,input,button{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,Liberation Mono,monospace}.editor{flex:1;width:100%;background:#0e1120;color:#e8e8e8;border:none;padding:12px;resize:none;outline:none}.controls{display:flex;gap:8px;padding:10px;border-top:1px solid #22283e}button{background:var(--accent);color:#fff;border:none;border-radius:6px;padding:8px 12px;cursor:pointer}button.secondary{background:#2a2f4a}.io{display:flex;gap:8px;padding:8px}.io textarea{height:120px}pre.output{margin:0;padding:12px;white-space:pre-wrap;overflow:auto;flex:1}.status{color:var(--muted);padding:8px 12px}