如何使用CSS在灵活宽度设计中设置自动边距框？

I have DIV with flexible width set e.g. min-width:800px and max-width:1400px. In this DIV, there are many boxes with fix width 200px and display:inline-block. So depending on parent DIV width, these boxes fill the entire space. I have DIV with flexible width set e.g. min-wid