APPOINTMENT DETAILS NOT RESPONSIVE - APPOINTMENTS +

I tried to set the width 100% for almost every element in that section but nothing really changes can you help me which class do i need to set to 100% to make this responsive?

Here are my css changes

.appointments-confirmation-buttons, .appointments-confirmation-button,.appointments-confirmation-cancel-button,.appointments-confirmation-wrapper span {clear:both;width: 100%;}
.appointments-confirmation-wrapper, .su-spoiler, .appointments-confirmation-wrapper fieldset, .appointments-confirmation-wrapper fieldset legend,.appointments-confirmation-wrapper label,.appointments-confirmation-wrapper fieldset div, .appointments-confirmation-wrapper fieldset div label, .appointments-confirmation-wrapper fieldset  div  {clear:both;width: 100%;overflow:hidden;box-sizing: border-box}

Access the page here http://englishmilestones.com/appointments-pay-as-you-go/