You probably know this but it's because when you include the jquery-mobile script, it adds a bunch of CSS rules to your page. I have a temporary solution but you'll want to find a better one eventually:In tundra.css, change the following from relative to absolute:
.dijitBorderContainer, .dijitBorderContainerNoGutter {
overflow: hidden;
position: relative;
z-index: 0;
}
.dijitBorderContainer, .dijitBorderContainerNoGutter {
overflow: hidden;
position: absolute;
z-index: 0;
}