Make the Facebook Like Box responsive

This is a CSS only solution I found online. Add the following code to your .css file:

.fb-comments, .fb-comments iframe[style], .fb-like-box, .fb-like-box iframe[style] {width: 100% !important;display:block;z-index:2000;position:relative}
.fb-comments span, .fb-comments iframe span[style], .fb-like-box span, .fb-like-box iframe span[style] {width: 100% !important;display:block;z-index:2000;position:relative}

When you get the Like Box code, you need to remove the width in the source link attributes and change it to 100% in the iframe properties:

<iframe src="//www.facebook.com/plugins/likebox.php?href=https.............&amp;width=200&amp;height=395&amp;colorscheme=light&amp;show_faces=false&amp;header=false&amp;stream=true&amp;show_border=false" scrolling="no" frameborder="0" style="border:none; overflow:hidden; width:100%; height:395px;" allowTransparency="true"></iframe>

It works!