Bootstrap modals don't work correctly on Android and iOS. The issue tracker acknowledges the problem but does not offer a working solution:
Modals in 2.0 are broken on mobile.
Modal window in 2.0 not positioning properly
The screen darkens but the modal itself is not visible in the viewport. It's possible to find it at the top of the page. The problem occurs when you've scrolled down on the page.
Here is a relevant portion of bootstrap-responsive.css:
.modal {
position:fixed;
top:50%;
left:50%;
z-index:1050;
max-height:500px;
overflow:auto;
width:560px;
background-color:#fff;
border:1px solid #999;
-webkit-border-radius:6px;
-moz-border-radius:6px;
border-radius:6px;
-webkit-box-shadow:0 3px 7px rgba(0, 0, 0, 0.3);
-moz-box-shadow:0 3px 7px rgba(0, 0, 0, 0.3);
box-shadow:0 3px 7px rgba(0, 0, 0, 0.3);
-webkit-background-clip:padding-box;
-moz-background-clip:padding-box;
background-clip:padding-box;
margin:-250px 0 0 -280px;
}
Is there a fix I can apply?
EDIT: An unofficial Bootstrap Modal modification has been built to address responsive/mobile issues. This is perhaps the simplest and easiest way to remedy the problem.
There has since been a fix found in one of the issues you discussed earlier
in bootstrap-responsive.css
.modal {
position: fixed;
top: 3%;
right: 3%;
left: 3%;
width: auto;
margin: 0;
}
.modal-body {
height: 60%;
}
and in bootstrap.css
.modal-body {
max-height: 350px;
padding: 15px;
overflow-y: auto;
-webkit-overflow-scrolling: touch;
}