$(document).ready(function() {

prepareForMobile();
newgame();

})

function prepareForMobile(){

if( documentWidth > 500){
    gridContainerWidth = 460;
    cellSpace = 20;
    cellSideLength = 100;
}
$('#grid-container').css('width', gridContainerWidth );
$('#grid-container').css('height', gridContainerWidth);
$('#grid-container').css('padding', cellSpace);
$('#grid-container').css('border-radius', 0.02*gridContainerWidth);

$('.grid-cell').css('width', cellSideLength);
$('.grid-cell').css('height', cellSideLength);
$('.grid-cell').css('border-radius', 0.02*cellSideLength);

}

为什么我这个代码不能实现屏幕自适应，出现下图情况