body {
    background: #e3efff;
    color: #183153;
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

h1 {
    color: #2563c9;
    text-align: center;
    margin-top: 40px;
    margin-bottom: 30px;
}

form {
    max-width: 350px;
    margin: 60px auto;
    background: #d0e3ff;
    border-radius: 9px;
    padding: 25px 30px 20px 30px;
    box-shadow: 0 0 15px #b4cff9, 0 2px 15px #dceafe inset;
}

label {
    font-weight: 600;
    color: #2166b3;
    letter-spacing: 0.03em;
}

input[type="number"] {
    width: 80px;
    padding: 7px;
    margin: 10px 10px 15px 0;
    border: 1px solid #6fa1e7;
    border-radius: 4px;
    background: #eef6ff;
    color: #102541;
    font-size: 17px;
}

input[type="submit"] {
    padding: 8px 20px;
    background: #2563c9;  
    border: none;
    color: #fff;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    box-shadow: 0 2px 5px #c3d9f7;
}

input[type="submit"]:hover {
    background: #154486;   
}


body > div.result {
    max-width: 350px;
    margin: 50px auto;
    background: #d0e3ff;
    border-radius: 9px;
    padding: 22px 18px;
    box-shadow: 0 0 15px #b4cff9, 0 2px 15px #dceafe inset;
    text-align: center;
    font-size: 18px;
}