main {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
    font-family: Arial, sans-serif;
}

a {
    color: #007bff;
}

input,
button {
    width: 100%;
    padding: 10px;
    margin: 10px 0;
    box-sizing: border-box;
}

input {
    &[type="checkbox"] {
        width: auto;
        margin-right: 10px;
    }
}

section,
form {
    max-width: 400px;
    margin: 0 auto;
}

ul li {
    margin-top: 4px;
}