body {
    font-family: sans-serif;
    background-color: #f0f4f8;
    padding: 40px;
    text-align: center;
}

h1 {
    color: #333;
    margin-bottom: 20px;
}

#num-of-challenge {
    font-size: 1.2rem;
    margin-bottom: 20px;
}

input[type="number"] {
    padding: 10px;
    font-size: 1.2rem;
    width: 200px;
    border: 2px solid #ccc;
    border-radius: 5px;
    margin-right: 10px;
}

button {
    padding: 10px 20px;
    font-size: 1.1rem;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    margin: 10px;
}

button:hover {
    background-color: #0056b3;
}

#errorLog {
    color: red;
    font-size: 0.95rem;
    margin-top: 10px;
    height: 1.2em;
}

#result {
    font-size: 1.3rem;
    transition: all 0.3s;
}

#result.correct {
    color: green;
}

#result.high, #result.low {
    color: #555;
}

#result.gameover {
    color: red;
    font-size: 1.6rem;
}

#reset {
    background-color: #6c757d;
}

#reset:hover {
    background-color: #495057;
}