email-styles.php

<?php
/**
 * Email Styles
 *
 * This template can be overridden by copying it to yourtheme/woocommerce/emails/email-styles.php.
 *
 * HOWEVER, on occasion WooCommerce will need to update template files and you
 * (the theme developer) will need to copy the new files to your theme to
 * maintain compatibility. We try to do this as little as possible, but it does
 * happen. When this occurs the version of the template file will be bumped and
 * the readme will list any important changes.
 *
 * @see     https://docs.woocommerce.com/document/template-structure/
 * @package WooCommerce\Templates\Emails
 * @version 4.0.0
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

// Load colors.
$bg        = get_option( 'woocommerce_email_background_color' );
$body      = get_option( 'woocommerce_email_body_background_color' );
$base      = get_option( 'woocommerce_email_base_color' );
$base_text = wc_light_or_dark( $base, '#202020', '#ffffff' );
$text      = get_option( 'woocommerce_email_text_color' );

// Pick a contrasting color for links.
$link_color = wc_hex_is_light( $base ) ? $base : $base_text;

if ( wc_hex_is_light( $body ) ) {
	$link_color = wc_hex_is_light( $base ) ? $base_text : $base;
}

$bg_darker_10    = wc_hex_darker( $bg, 10 );
$body_darker_10  = wc_hex_darker( $body, 10 );
$base_lighter_20 = wc_hex_lighter( $base, 20 );
$base_lighter_40 = wc_hex_lighter( $base, 40 );
$text_lighter_20 = wc_hex_lighter( $text, 20 );
$text_lighter_40 = wc_hex_lighter( $text, 40 );

// !important; is a gmail hack to prevent styles being stripped if it doesn't like something.
// body{padding: 0;} ensures proper scale/positioning of the email in the iOS native email app.
?>
body {
	padding: 0;
}

#wrapper {
	background-color: <?php echo esc_attr( $bg ); ?>;
	margin: 0;
	padding: 70px 0;
	-webkit-text-size-adjust: none !important;
	width: 100%;
}

#template_container {
	box-shadow: 0 1px 4px rgba(0, 0, 0, 0.1) !important;
	background-color: <?php echo esc_attr( $body ); ?>;
	border: 1px solid <?php echo esc_attr( $bg_darker_10 ); ?>;
	border-radius: 3px !important;
}

#template_header {
	background-color: <?php echo esc_attr( $base ); ?>;
	border-radius: 3px 3px 0 0 !important;
	color: <?php echo esc_attr( $base_text ); ?>;
	border-bottom: 0;
	font-weight: bold;