Opening Cord — Back to Opening

Source Code

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

<button aria-label="ページの先頭、舞台の開幕に戻る" class="btt-control btt-2086 btt-hidden" data-btt="" type="button"><span aria-hidden="true" class="cord-rail"><span class="cord-top"></span><span class="cord-strand"></span></span><span class="cord-token"><span class="cord-star">✦</span><b>OPENING</b><small>BACK TO<br/>THE BEGINNING</small></span><span aria-hidden="true" class="cord-meter"></span></button>

 .btt-control{box-sizing:border-box;appearance:none;cursor:pointer;user-select:none;-webkit-tap-highlight-color:transparent}.btt-control:focus-visible{outline:3px solid #e6a643;outline-offset:5px}.btt-hidden{opacity:0;visibility:hidden;pointer-events:none}.btt-visible{opacity:1;visibility:visible;pointer-events:auto} @media(prefers-reduced-motion:reduce){.btt-control,.btt-control *{animation-duration:.01ms!important;transition-duration:.01ms!important}}
 .btt-2086{position:fixed;right:clamp(17px,3vw,44px);top:17%;z-index:40;width:119px;height:230px;border:0;background:transparent;color:#f2dfc0;opacity:0;transform:translateY(-18px);transition:opacity .3s,transform .3s,visibility .3s}.btt-2086.btt-visible{opacity:1;transform:none}.cord-rail{display:block;position:absolute;top:0;left:47px;width:26px;height:116px}.cord-top{display:block;width:14px;height:14px;border:2px solid #e6c58d;border-radius:50%;margin:auto;background:#3f2832}.cord-strand{display:block;width:2px;height:100px;margin:auto;background:repeating-linear-gradient(#e7ba87 0 5px,#a67657 6px 9px);transform-origin:top;animation:cordSway 5s ease-in-out infinite}.cord-token{position:absolute;top:116px;left:4px;width:111px;height:100px;border:1px solid #d5ac74;border-radius:7px;background:#5a263b;display:flex;align-items:center;flex-direction:column;justify-content:center;box-shadow:0 12px 28px #0007;transform-origin:top;animation:cordSway 5s ease-in-out infinite}.cord-star{font-size:16px;color:#e8b87b;animation:cordGlow 3s ease-in-out infinite}.cord-token b{font:800 13px/1.2 Arial;letter-spacing:.13em;margin:6px 0}.cord-token small{font:700 9px/1.35 Arial;letter-spacing:.08em}.cord-meter{position:absolute;bottom:2px;left:14px;width:90px;height:2px;background:linear-gradient(90deg,#e7be8e calc(var(--progress,0)*100%),#624e4a 0)}.btt-2086:hover .cord-strand{height:110px}.btt-2086:hover .cord-token{transform:translateY(8px)}.btt-2086.is-going .cord-token{background:#936140}.btt-2086:focus-visible{outline-offset:-10px}@keyframes cordSway{0%,100%{rotate:-1deg}50%{rotate:2deg}}@keyframes cordGlow{0%,100%{opacity:.55}50%{opacity:1}}@media(max-width:600px){.btt-2086{right:10px;top:auto;bottom:14px;width:104px;height:170px}.cord-rail{left:44px;height:67px}.cord-strand{height:58px!important}.cord-token{top:66px;left:0;width:104px;height:94px}.cord-meter{width:78px;left:13px}}

(()=>{'use strict';const el=document.querySelector('[data-btt]');if(!el)return;const footerOnly=false;const reduce=window.matchMedia('(prefers-reduced-motion: reduce)');let raf=0;function update(){raf=0;const p=Math.max(0,Math.min(1,window.scrollY/Math.max(1,document.documentElement.scrollHeight-window.innerHeight)));if(!footerOnly){const shown=window.scrollY>170;el.classList.toggle('btt-visible',shown);el.classList.toggle('btt-hidden',!shown);el.tabIndex=shown?0:-1;el.setAttribute('aria-hidden',String(!shown));}el.style.setProperty('--progress',p.toFixed(3));const field=el.querySelector('[data-state]');}function onScroll(){if(!raf)raf=requestAnimationFrame(update)}window.addEventListener('scroll',onScroll,{passive:true});window.addEventListener('resize',onScroll,{passive:true});el.addEventListener('click',()=>{el.classList.add('is-going');window.scrollTo({top:0,behavior:reduce.matches?'auto':'smooth'});window.setTimeout(()=>el.classList.remove('is-going'),650)});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

Theatres, exhibitions and event sites.

Technical Notes

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

Mobile：Check tap target, visibility and positioning on small screens.

Browser：Designed for current Chrome, Edge, Firefox and Safari.

Reduced Motion：CSS animations respect the reduced-motion preference.