body {
    font-family: Arial;
    background: linear-gradient(to right, #74ebd5, #9face6);
    text-align: center;
}

.container {
    background: white;
    width: 320px;
    margin: 100px auto;
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 0 15px gray;
}

input {
    width: 90%;
    padding: 10px;
    margin: 8px;
    border-radius: 5px;
    border: 1px solid #ccc;
}

button {
    padding: 10px 20px;
    background: #4CAF50;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

button:hover {
    background: #45a049;
}

#result {
    margin-top: 15px;
    font-weight: bold;
}

.error {
    color: red;
}