Resize the browser window. When the width of this document is 600 pixels or less, the background-color is "lightblue", otherwise it is "lightgreen".

@media only works when it's at the bottom of style. Works in vertical view (up to 412px). Link How to get something to work in horizontal view is unknown. Even I can't do it with this file.. have to know what the size should be in order for it to work like with vertical view. Making changes in font styles between the two doesn't work. Font sizes doesn't seem to work. Practice using this file before any site gets changes in mobile.