There is a property in the web.config file for configuring the style sheet theme of your total website.
Here is a sample. You can try this.It may be a way to solve your first problem.
<system.web>
<pages styleSheetTheme="Default" enableEventValidation="false" controlRenderingCompatibilityVersion="4.0" clientIDMode="Predictable"/></system.web>
Thanks & Happy Coding.