Can't scroll to top of flex item that is overflowing container

Question

So, in attempting to make a useful modal using flexbox, I found what seems to be a browser issue and am wondering if there is a known fix or workaround -- or ideas on how to

Answer 1

2 Container Flex Method with Table fallback tested IE8-9, flex works in IE10,11. Edit: Edited to ensure vertical centering when minimal content, added legacy support.

The issue stems from height being inherited from the viewport size which causes children to overflow, as Michael answered. https://stackoverflow.com/a/33455342/3500688

something more simple and use flex to maintain the layout within the popup container(content):

#popup {
position: fixed;
top: 0;
left: 0;
right: 0;
min-height: 100vh;
background-color: rgba(0,0,0,.25);
margin: auto;
overflow: auto;
height: 100%;
bottom: 0;
display: flex;
align-items: flex-start;
box-sizing:border-box;
padding:2em 20px;
}
.container {
background-color: #fff;
margin: auto;
border: 1px solid #ccc;
border-radius: 4px;
background: #fff;
/* width: 100%; */
max-width: 500px;
padding: 10px;
    /* display: flex; */
    /* flex-wrap: wrap; */
}
		

	
    

        
Test
    
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Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.