Optimize HTML Code for display in Internet Explorer

Dear Community, My HTML Code for an introduction code within my survey works fine - as long as I do not use Internet explorer. Could you please help me to teak it, so that my questions (whih I am using for an introduction text) will be displayed in the centre of the page? - currently it is shown on the left side of the explorer (while working perfectly on firefox/chrome, displaying the text in the centre) Is there a certain code that I need to add in order to trigger the centering within IE ? It would be important that * The code works on IE, Firefox, Chrome, Safari, Mobile * It is properly displayed for different screen sizes This is my (exemplary)code for headline, Text and a Subheadline, which I would like to be displayed in the center of the screen on IE when opening the survey: ! ... Thank you very much in advance or your help! Best regards