.form-text[data-headless-selector] {
    margin-bottom: 3em;
}

.form-text[data-headless-selector]::before {
    content: "置換コンテンツ（PC）";
}

.form-text.form-text-sp[data-headless-selector]::before {
    content: "埋め込みコンテンツ（スマホ）";
}

div#undercolumn_login+div[data-headless-selector]::before {
    content: "埋め込みコンテンツ（PC・スマホ共通）";
}