CSS to reduce the size of the message page alone:
/** Title font size **/
.surveysparrow-survey-container--classic-form .ss_cl_survey_qstn_item[data-qa-question-type="Message"] .ss_cl_survey_qstn h1 {
font-size: 28px;
}
/** Description font size **/
.surveysparrow-survey-container--classic-form .ss_cl_survey_qstn_item[data-qa-question-type="Message"] .ss_cl_survey_qstn .ss-survey-question-description {
font-size: 14px;
}
