:root{
  --bg:#f8fafc;
  --card:#ffffff;
  --accent:#0ea5a4;
  --muted:#64748b;
}
*{box-sizing:border-box;font-family:Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;}
body{margin:0;background:linear-gradient(180deg,#e6fffa,white);color:#0f172a;min-height:100vh;display:flex;flex-direction:column;}
.topbar{display:flex;justify-content:space-between;align-items:center;padding:14px 20px;background:var(--card);box-shadow:0 2px 8px rgba(2,6,23,0.06);}
.container{padding:20px;max-width:920px;margin:20px auto;flex:1;display:grid;gap:18px;grid-template-columns:1fr 1fr;}
.card{background:var(--card);padding:16px;border-radius:12px;box-shadow:0 6px 18px rgba(2,6,23,0.06);}
.btn{background:var(--accent);border:none;color:white;padding:8px 12px;border-radius:8px;cursor:pointer;}
.hidden{display:none;}
#notesList{list-style:none;padding:0;margin-top:12px;display:flex;flex-direction:column;gap:8px;}
#notesList li{padding:10px;border-radius:8px;background:#f1f5f9;border:1px solid #e2e8f0;display:flex;justify-content:space-between;align-items:center;}
footer.footer{text-align:center;padding:12px;color:var(--muted);font-size:13px;}
@media (max-width:800px){
  .container{grid-template-columns:1fr; padding:12px;}
}