Using HTML5 Boilerplate to start your project would be the best choice because it sets the perfect default HTML page for your PC/Mobile project. The H5BP (HTML5 Boilerplate) makes sure that your page is working fine on all devices/browsers.
The default CSS that comes with H5BP has some issues with browser compatibilities. Don’t worry about that, I have fixed all browser compatibility issues in the CSS and it is attached here. Download and replace it with the default CSS file that comes with H5BP (style.css).