To change the font size of Event title, Please follow the instruction below:
Please do remember to back-up the files prior to any change.
1) Open css/layout.css in the theme folder.
2) Add the following code to the end of the style-sheet.
section.fullwidth.site-slider .slider-content h1{ font-size: 50px;}
Change 50px with any value according to your requirement.
3) Save the file.