styles.css

body.options {
    padding: 20px 0;
}

h1 {
    margin-top: 0;
}

.options ul {
    margin: 0;
    padding: 0;
}

.options ul li {
    list-style: none;
    padding: 10px 0;
    margin-bottom: 15px;
    background: white;
}

.options ul li h2 {
    padding: 0;
    margin: 0;
}
.options ul li input {
    width: 20em;
    margin: 0;
    padding: 0.25em 0.5em;
}
.options ul li select {
    width: 10em;
    margin: 0;
    padding: 0.25em 0.5em;
}

.options ul li input[type=checkbox] {
    -moz-transform: scale(1.5); /* FF */
    -webkit-transform: scale(1.5); /* Safari and Chrome */
    padding: 10px;
    margin-right: 10px;
}

.options .formItemContainer {
    margin-bottom: 0.5em;
    display: flex;
    align-items: center;
}

.options .formItem {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.options .formItem input,
.options .formItem select {
    flex-grow: 2;
}

.options .buttons {
    text-align: left;
}

.options form button[type=submit] {
    font-size: 1.3em;
    width: 15%;
    text-align: center;
}

.options form label {
    display: inline-flex;
    width: 5em;
    margin: 0.2em 0;
}

.options .u-isHidden {
    display: none;
}

.options .help {
    margin-left: 0.5em;
}

.options .samesiteSecureInfo {
    margin-left: 5.1em;
}

.msg {
    margin-left: 1em;
}

.msg-ok {
    color: #1d6218;
}

@media only screen and (max-width: 400px) {
    .options .formItemContainer {
        flex-direction: column;
        align-items: normal;
    }

    .options .formItemContainer > * {
        margin-right: 5px;
    }

    .options .samesiteSecureInfo {
        margin-left: 0;
    }
}