body{color:#172033;background:#f5f7fb;margin:0;font-family:system-ui}main{background:#fff;border-radius:12px;max-width:640px;margin:48px auto;padding:24px;box-shadow:0 2px 12px #0001}form{gap:8px;display:flex}input:not([type=checkbox]){border:1px solid #ccd3df;border-radius:6px;flex:1;padding:10px}button{color:#fff;cursor:pointer;background:#2563eb;border:0;border-radius:6px;padding:9px 14px}ul{padding:0;list-style:none}li{border-bottom:1px solid #eee;justify-content:space-between;align-items:center;padding:12px 0;display:flex}.done{color:#8490a3;text-decoration:line-through}.error{color:#c62828}