PROGRESS — Back to Top

Source Code

Copy the HTML, CSS or JavaScript you need for your project.

<button type="button" class="tb-btt-button tb-btt-2006 is-hidden" aria-label="Back to the top of the page" title="Back to Top"><span class="art art-progress"><svg viewBox="0 0 100 100" focusable="false" aria-hidden="true" xmlns="http://www.w3.org/2000/svg"><circle class="progress-back" cx="50" cy="50" r="37" fill="none" stroke="currentColor" stroke-opacity=".15" stroke-width="2.1"/><circle class="progress-front" cx="50" cy="50" r="37" fill="none" stroke="currentColor" stroke-width="2.8" stroke-linecap="round" transform="rotate(-90 50 50)"/><path class="progress-arrow" d="M50 68V36M39 47 50 36 61 47" fill="none" stroke="currentColor" stroke-width="2.4" stroke-linecap="round" stroke-linejoin="round"/></svg></span></button>

/* TB-2006 — Back to Top button. */
.tb-btt-2006{--selectedtone:#467e77;color:#467e77;position:fixed;right:max(18px,env(safe-area-inset-right));bottom:max(18px,env(safe-area-inset-bottom));z-index:1000;border:0;background:transparent;padding:5px;display:flex;align-items:center;justify-content:center;min-width:48px;min-height:48px;cursor:pointer;font-family:Arial,"Noto Sans JP",sans-serif;line-height:normal;box-sizing:border-box;-webkit-tap-highlight-color:transparent;transition:opacity .24s ease, transform .35s ease,visibility .24s ease}
.tb-btt-2006:is(:focus-visible){outline:2px solid currentColor;outline-offset:4px}
.tb-btt-2006.is-hidden{opacity:0;transform:translateY(10px);visibility:hidden;pointer-events:none}
.tb-btt-2006 *{box-sizing:border-box}
.tb-btt-2006 .art{display:flex;position:relative;align-items:center;justify-content:center;flex-shrink:0}
.tb-btt-2006 .art svg{display:block;overflow:visible;width:100%;height:100%}

.tb-btt-2006 .art-progress{width:61px;height:61px}
.tb-btt-2006 .progress-front{stroke-dasharray:232.48;stroke-dashoffset:var(--offset,65.1);transition:stroke-dashoffset .1s linear}
.tb-btt-2006 .progress-arrow{transform-origin:50px 50px;transition:transform .35s}

.tb-btt-2006:is(:hover,:focus-visible) .progress-arrow{transform:translateY(-5px)}

.tb-btt-2006 .art{color:var(--selectedtone,#465b53)}
@media(prefers-reduced-motion:reduce){.tb-btt-2006,.tb-btt-2006 *, .tb-btt-2006 *::before,.tb-btt-2006 *::after{animation-duration:0.01ms!important;animation-iteration-count:1!important;transition-duration:0.01ms!important}}

/* TB-2006 | Back to Top | No external libraries required. */
(() => {
  'use strict';

  const button = document.querySelector('.tb-btt-2006');
  if (!button) return;

  const reduceMotion = window.matchMedia('(prefers-reduced-motion: reduce)');
  let scheduled = false;

  function update() {
    scheduled = false;
    const visible = window.scrollY > 160;
    button.classList.toggle('is-hidden', !visible);
    button.tabIndex = visible ? 0 : -1;
    button.setAttribute('aria-hidden', String(!visible));
    const maxScroll = Math.max(1, document.documentElement.scrollHeight - window.innerHeight);
    const progress = Math.max(0, Math.min(1, window.scrollY / maxScroll));
    const ring = button.querySelector('.progress-front');
    if (ring) ring.style.strokeDashoffset = (232.48 * (1 - progress)).toFixed(2);
  }

  function requestUpdate() {
    if (scheduled) return;
    scheduled = true;
    requestAnimationFrame(update);
  }

  button.addEventListener('click', () => {
    window.scrollTo({ top: 0, behavior: reduceMotion.matches ? 'auto' : 'smooth' });
  });
  window.addEventListener('scroll', requestUpdate, { passive: true });
  window.addEventListener('resize', requestUpdate, { passive: true });
  update();
})();

How to Use

Insert the HTML button near the end of body, load the CSS, and include JavaScript using defer. Test scrolling, returning to the top, and positioning on mobile.

Use Case

Long-form content and reading-heavy pages

Technical Notes

Keep controls usable on touch devices. Test keyboard focus and reduced-motion preferences.

Mobile：Works with tap and keyboard. Check the lower-right offset against other fixed controls.

Browser：Uses standard HTML, CSS and JavaScript. Install all three together; no external library is required.

Reduced Motion：Reduces transitions and smooth scrolling when reduced motion is requested.