:root{font-family:Inter,system-ui,sans-serif;background-color:#1a202c;color:#e2e8f0}body{margin:0;padding:0}.container{max-width:800px;margin:0 auto;padding:15px}.grid{display:grid;grid-template-columns:1fr;gap:15px}@media(min-width:600px){.grid{grid-template-columns:1fr 1fr}}.card{background-color:#2d3748;padding:20px;border-radius:12px;border:1px solid #4a5568;box-shadow:0 4px 6px #0003}input,button{font-size:1rem;padding:12px;border-radius:8px;border:1px solid #4a5568}button{cursor:pointer;font-weight:700;transition:transform .1s}button:active{transform:scale(.98)}.btn-primary{background-color:#4fd1c5;color:#1a202c;border:none}.btn-danger{background-color:#fc8181;color:#fff;border:none}