当我调整窗口大小时，如何防止所有flex项目调整大小？

I have tried using the following on my flex-container after clicking on my button to generate the content, but when I resize the windows, it keeps resizing my items. I want them to have a fixed width and height (ideally each item would be a square of 100x100 px)I have tried using the following on my flex-con