body {
    display: flex;
    flex-direction: column;
    align-items: center;
    font-family: Arial, sans-serif;
    background: #f5f7fa;
    color: #333;
    margin: 0;
    padding: 20px;
}

.div1{
    background-color: #ffffff;
    max-width: 425px;
    min-width: 425px;
    border: 8px #ddd;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    padding: 10px;
    margin-bottom: 10px;
}

h1{
    text-align: center;
    margin-bottom: 20px;
}

form {
    max-width: 100%;
    display: flex;
    flex-direction: column;
    background: #ffffff;
    color: #333;
    font-family: Arial, sans-serif;
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 15px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    margin-bottom: 25px;
}

.number-input {
    max-width: 100%;
    padding: 8px;
    margin: 8px 0 16px 0;
    border: 1px solid #ccc;
    border-radius: 5px;
    font-size: 1em;
    box-sizing: border-box;
}

.submit-btn {
    background-color: #007acc;
    color: white;
    border: none;
    padding: 10px 15px;
    font-size: 1em;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.submit-btn:hover {
    background-color: #005c99;
}