Set oEmbed Maximum Width

<?php
/**
 * Limits the width of oEmbed content (YouTube, Vimeo, Twitter, etc.).
 * Adjust the value below to match your theme's content column width.
 */
if ( ! function_exists( 'scseed_oembed_max_width' ) ) {
    function scseed_oembed_max_width( $defaults ) {
        $defaults['width'] = 800; // Maximum embed width in pixels.
        return $defaults;
    }
    add_filter( 'embed_defaults', 'scseed_oembed_max_width' );
}