Content not shown on some older browsers and mobile devices (SGS3)

It is your css. I went into the your CSS and for .content-area. I took out the float left and then went into

line 753

and took out the display:table. I am not sure on this theme but if it is using tables I would change it all to div’s

.footer-sidebar::before, 
.footer-sidebar::after, 
.hentry::before, 
.hentry::after, 
.slider-direction-nav::before, 
.slider-direction-nav::after, 
.contributor-info::before, 
.contributor-info::after, 
.search-box::before, 
.search-box::after, [class*="content"]::before, [class*="content"]::after,
[class*="site"]::before, 
[class*="site"]::after {
    content: "";
    display: table;
}

That is what displayed it for me but without the actual code I am only seeing those two things wrong. You do not have to take out the display table but just take out class content part and you might be fine.

[class*="content"]::before, [class*="content"]::after,

I am not 100 percent sure but I know that is where your problem is.