butexe.js

let originalFont;
  let currentFontSize = 0;

  function setFont(font) {
    document.body.style.fontFamily = font;
    localStorage.setItem('font', font);
  }

  function setFontSize(size) {
    currentFontSize = parseInt(window.getComputedStyle(document.body).getPropertyValue('font-size'));
    currentFontSize += size;
    document.body.style.fontSize = currentFontSize + 'px';
    localStorage.setItem('fontSize', currentFontSize + 'px');
  }

  document.addEventListener('DOMContentLoaded', () => {
    originalFont = window.getComputedStyle(document.body).getPropertyValue('font-family');
    localStorage.setItem('originalFont', originalFont);
    let font = localStorage.getItem('font');
    if (!font) {
      font = originalFont;
    }
    document.body.style.fontFamily = font;

    let fontSize = localStorage.getItem('fontSize');
    if (!fontSize) {
      fontSize = '16px';
    }
    document.body.style.fontSize = fontSize;

    const fontButtonContainer = document.createElement('div');
    fontButtonContainer.style.display = 'flex';
    fontButtonContainer.style.justifyContent = 'center';
    fontButtonContainer.style.alignItems = 'center';

    const standardFontButton = document.createElement('a');
    standardFontButton.classList.add('font-button');
    standardFontButton.textContent = 'Fuente estándar';
    standardFontButton.addEventListener('click', () => setFont(originalFont));
    fontButtonContainer.appendChild(standardFontButton);

    const dyslexicFontButton = document.createElement('a');
    dyslexicFontButton.classList.add('font-button');
    dyslexicFontButton.textContent = 'OpenDyslexic';
    dyslexicFontButton.addEventListener('click', () => setFont('OpenDyslexic, sans-serif'));
    fontButtonContainer.appendChild(dyslexicFontButton);

    const hyperlegibleFontButton = document.createElement('a');
    hyperlegibleFontButton.classList.add('font-button');
    hyperlegibleFontButton.textContent = 'Atkinson Hyperlegible';
    hyperlegibleFontButton.addEventListener('click', () => setFont('Atkinson Hyperlegible, sans-serif'));
    fontButtonContainer.appendChild(hyperlegibleFontButton);

    const increaseFontButton = document.createElement('button');
    increaseFontButton.classList.add('font-button');
    increaseFontButton.textContent = '+';
    increaseFontButton.addEventListener('click', () => setFontSize(3));
    fontButtonContainer.appendChild(increaseFontButton);

    const decreaseFontButton = document.createElement('button');
    decreaseFontButton.classList.add('font-button');
    decreaseFontButton.textContent = '-';
    decreaseFontButton.addEventListener('click', () => setFontSize(-3));
    fontButtonContainer.appendChild(decreaseFontButton);

    document.body.insertBefore(fontButtonContainer, document.body.firstChild);

    const infoLink = document.createElement('a');
    infoLink.textContent = '+Info';
    infoLink.href = 'https://bilateria.org/fuente/';
    infoLink.target = '_blank';
    infoLink.style.marginLeft = '8px';
    infoLink.style.fontSize = '12px';
    fontButtonContainer.appendChild(infoLink);
  });