Wordpress responsive youtube embeds

css.css

.embed-container {
    height: auto;
    max-width: 100%;
    overflow: hidden;
    padding-bottom: 56.25%;
    padding-top: 30px;
    position: relative;
}
.embed-container iframe,
.embed-container object,
.embed-container embed {
    height: 100%;
    left: 0;
    position: absolute;
    top: 0;
    width: 100%;
}

functions.php

<?php
if ( ! isset( $content_width ) ) $content_width = 830;
function embed_responsively($iframe) {
	return '<div class="embed-container">'.$iframe.'</div>';
}
add_filter('oembed_result', 'embed_responsively');