body {
    font-family: Arial, sans-serif;
    background: linear-gradient(to right, #1f2020, #292c2c3a);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.container {
    background: rgb(221, 221, 221);
    padding: 25px;
    border-radius: 15px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    width: 320px;
    text-align: center;
}

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

label {
    display: block;
    margin-top: 10px;
    font-weight: bold;
    color: #555;
}

input[type="number"] {
    width: 90%;
    padding: 8px;
    margin-top: 5px;
    border: 1px solid #ccc;
    border-radius: 8px;
    font-size: 14px;
}

input[type="checkbox"] {
    margin-right: 5px;
}

button {
    margin-top: 15px;
    padding: 10px 20px;
    border: none;
    background: #213444ab;
    color: white;
    font-size: 16px;
    border-radius: 8px;
    cursor: pointer;
    transition: 0.3s;
}

button:hover {
    background: #213444ab;
}

.result {
    margin-top: 15px;
    font-size: 18px;
    font-weight: bold;
    color: #333;
}