InlineStylesCK.js

/**
 * Run in the console to inline all code block styles before
 * copy + pasting into ConvertKit in HTML mode
 */

const CSS_PROPERTIES = [
  'background-color',
  'font-size',
  'color',
];

const arr = document.querySelectorAll('pre, pre *');
arr.forEach(el => {
  // Grab computed styles
  const styles = getComputedStyle(el);

  // Generate inline style and apply
  el.style = CSS_PROPERTIES.reduce((prev, next) => {
    prev += `${next}: ${styles.getPropertyValue(next)}; color-scheme: only light;`
    return prev;
  }, '');
});

let html = document.querySelector('.content').innerHTML;

// Escape interpolation
html = html.replaceAll('{{', '{% raw %}{{');
html = html.replaceAll('}}', '}}{% endraw %}');

console.log(html);