body{margin:0;font-family:Inter,Arial,sans-serif;background:#081018;color:#fff;display:flex}
.sidebar{width:240px;height:100vh;background:#111827;padding:20px}
.sidebar button{width:100%;margin:6px 0;padding:12px;background:#1f2937;color:#fff;border:0;border-radius:8px}
.main{flex:1;padding:24px}.hidden{display:none}.tab{display:block}