
I have three divs in content div, When browser resizing
Use flex-grow. Set it to 0 for the blue and red container, and something big for the green one:
.red{
height: 100%;
width:200px;
flex-grow: 0;
display:inline-block;
background-color: red;
}
.green{
height: 100%;
min-width:400px;
flex-grow: 1000;
display:inline-block;
background-color:green;
}
.blue{
height: 100%;
width:400px;
flex-grow: 0;
display:inline-block;
background-color: blue;
}
A very good cheat sheet can be found here: https://css-tricks.com/snippets/css/a-guide-to-flexbox/
Also, don't forget the other properties like display: flex;and justify-content: space-between. It's perfectly explained in the above link.
Note, however, that you don't have to use flexbox. you can achieve the same with float, which makes it compatible with older browsers (To do so, just use display: block; and add float: left to the blue div and float: right; to the red one.)