Try apply this following custom css code into your site backend > Easyblog > theme > custom css
#eb .form-group--float-label ::-webkit-input-placeholder {
color: transparent !important;
}
#eb .form-group--float-label :-moz-placeholder {
color: transparent !important;
}
#eb .form-group--float-label ::-moz-placeholder {
color: transparent !important;
}
#eb .form-group--float-label :-ms-input-placeholder {
color: transparent !important;
}
#eb .form-group--float-label input:-webkit-autofill ~ label {
font-size: 11px !important;
top: 6px !important;
}
#eb .form-group--float-label input:-webkit-autofill {
padding-top: 24px !important;
padding-bottom: 8px !important;
}
After you applied, you have to clear your browser and site backend cache before you test.