Force Tumblr on-blog controls to be mobile-style

fullWidthBlogFrame.js

const iframe = document.querySelector('iframe[src^="https://www.tumblr.com/dashboard/iframe"]');

const modifiedSrc = new URL(iframe.src);
const { hash } = modifiedSrc;

const decodedHash = decodeURIComponent(hash);
const parsedHash = JSON.parse(decodedHash.substring(1));
Object.assign(parsedHash, { isOpticaLike: true, useThemeColors: true });
const newHash = JSON.stringify(parsedHash);
const encodedHash = encodeURIComponent(newHash);
modifiedSrc.hash = `#${encodedHash}`;

const newFrame = iframe.cloneNode();
newFrame.src = modifiedSrc.href;

iframe.replaceWith(newFrame);
document.body.classList.remove('tmblr-iframe-overlay', 'tmblr-iframe-compact');
document.body.classList.add('tmblr-iframe-pushdown', 'tmblr-iframe-full-width');