How to show horizontal scrollbar if user resizes the window created on fullpage.js

I created a very simple webpage that uses fullPage.js script. Basically it works as the sample page provided by the author. Now, I would like to put there min-width on the page, so that when user decides to resize the window horizontally and make it small enough - instead of shrinking the divs inside - I would just display browser-native horizontal scrollbars. I tried to add either:

body {
    min-width: 900px;
    width: 100%;            
}

or the same in other css tag:

.section {
    text-align:center;
    width: 100%;
    min-width: 900px;
}

but none of those worked well. I found this communication with the author of the plugin, but I'm not exactly sure if his response is helpful enough. Can you help me with implementation of that feature? Thanks!