Fully Responsive Design
Html5 and CSS3 support any latest browser, operating system independent and device independent which calls to write once and use anywhere i.e cross-browser support. We can add many wow factor elements, which reduces the complexity of using flash objects on a web page. You can have full control over color palettes used for projects instead of keeping the separate code for the color theme.
So the conclusion is web-pages are more responsive than ever before, with minimal complexity in design to various platform without losing the quality of content and hence reduced bounce rate to web-pages with increased conversion rate.