Examples of custom CSS that can be used directly in Feedier surveys inside the Advanced Settings > Custom CSS option: 



Removing the questions count on the top right corner

#feedback-remaining {
    display:none;
}


Editing the logo size

#app-header .navbar-brand img {
    max-width: 200px;
    max-height: 100px !important;
}


Making the image options larger 

.feedback-question-form ul.image-select-type li {
       flex: 0 0 200px;
       max-width: 200px;
}

.feedback-question-form ul.image-select-type li a {
      height: 100px;
}