Hi,
1. You have to use ::placeholder and not :placeholder
https://developer.mozilla.org/en-US/docs/Web/CSS/::placeholder
2. Here is a plugin code:
.lrm-user-modal-container .input-text, .lrm-user-modal-container input[type=email], .lrm-user-modal-container input[type=password], .lrm-user-modal-container input[type=search], .lrm-user-modal-container input[type=tel], .lrm-user-modal-container input[type=text], .lrm-user-modal-container input[type=url], .lrm-user-modal-container select, .lrm-user-modal-container textarea {
background-color: #f7f7f7;
}
.lrm-user-modal-container .input-text:focus, .lrm-user-modal-container input[type=email]:focus, .lrm-user-modal-container input[type=password]:focus, .lrm-user-modal-container input[type=search]:focus, .lrm-user-modal-container input[type=tel]:focus, .lrm-user-modal-container input[type=text]:focus, .lrm-user-modal-container input[type=url]:focus, .lrm-user-modal-container select:focus, .lrm-user-modal-container textarea:focus {
border: 1px solid #d2d8d8;
box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.25);
}
So you could try just change the background-color
Max