form{max-width:400px;margin:2rem auto;padding:.5rem;background-color:#f9f9f9;border-radius:10px;box-shadow:0 4px 15px rgba(0,0,0,.1);display:flex;flex-direction:column;gap:.5rem}form input{padding:.75rem;border:1px solid #ccc;border-radius:5px;font-size:1rem;transition:border-color .3s,box-shadow .3s}form input:focus{border-color:#007bff;outline:none;box-shadow:0 0 5px rgba(0,123,255,.2)}.error{color:red;font-size:.875rem;margin-top:.25rem}.error-message{text-align:center}.btn{padding:.75rem;background-color:#007bff;color:#fff;font-size:1rem;font-weight:700;border:none;border-radius:5px;cursor:pointer;transition:background-color .3s}.btn:hover{background-color:#0056b3}@media (max-width:480px){form{padding:1.5rem;box-shadow:none;border-radius:0}form input{padding:.5rem;font-size:.9rem}.btn{padding:.6rem;font-size:.9rem}}