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JavaScript Reading & focus bbc.com

BBC: reading progress bar

Adds a thin red bar at the top of the page that shows how much of the article you have read.

Code to copy

// Add a thin reading-progress bar at the top of the page
(function () {
  if (document.getElementById('jz-bbc-progress')) { return; }
  var bar = document.createElement('div');
  bar.id = 'jz-bbc-progress';
  bar.style.cssText = 'position:fixed;top:0;left:0;height:3px;width:0;' +
    'background:#b80000;z-index:99999;transition:width .1s ease';
  document.body.appendChild(bar);
  function update() {
    var h = document.documentElement;
    var max = h.scrollHeight - h.clientHeight;
    var pct = max > 0 ? (h.scrollTop / max) * 100 : 0;
    bar.style.width = pct + '%';
  }
  window.addEventListener('scroll', update, { passive: true });
  update();
})();

How to use this example

  1. Copy the code with the button above.
  2. Install JustZix (2 minutes) and open the extension on the target page.
  3. Add a new rule matching that page.
  4. Paste the code into the rule's JavaScript panel and save — it runs on every page visit.

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