.wpcf7-not-valid-tip {font-size: 16px; margin-top: 5px}

.wpml-ls-native {display: inline-flex;color: #fff;text-decoration: underline;text-underline-offset: 5px;text-decoration-thickness: 0.5px;}
.wpml-ls-native::after {
    content: attr(lang);
}
.wpml-ls-native {
    font-size: 0; /* hide original */
}
.wpml-ls-native::after {
    font-size: 20px; /* your desired size */
    content: attr(lang); /* outputs 'fr', 'de', etc. */
    text-transform: uppercase;
}