WordPress Site Not Recognizing My Responsive CSS

In my header I have this set:

<meta charset="<?php bloginfo( 'charset' ); ?>" />
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
<title>

And in my style.css file, I have a section specifically for responsive display, that starts like this:

/* RESPONSIVE SETTINGS ————————————————————– */

/* Tablet (Portrait) /* Note: Design for a width of 768px */
@media only screen and (min-width: 768px) and (max-width: 959px) {
#wrapper { background:#476114; width:700px; margin:0 auto; height:auto }

I’ve used a similar setup in HTML sites, without issue. But for some reason this is not even registering when I look at the site in my Android phone or my iPad. Is there something else needed to make the responsive code be recognized?