Curtain Call — Return to Opening

Source Code

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

<!-- TB-2074 / Back to Top: insert before closing body (inside footer for TB-2083) -->
<button class="tb-btt bt2074" data-backtop type="button" aria-label="舞台の開幕、ページの先頭へ戻る"><span class="cord"></span><span class="pull">幕開けへ</span><span class="tassel"></span></button>

/* TB-2074 : paste only this CSS into the target page. */
.tb-btt{border:0;cursor:pointer;z-index:30;-webkit-tap-highlight-color:transparent;touch-action:manipulation;transition:transform .35s,opacity .3s,background .3s,color .3s,box-shadow .3s;pointer-events:none;opacity:0;visibility:hidden}.tb-btt.is-visible{pointer-events:auto;opacity:1;visibility:visible}.tb-btt:focus-visible{outline:3px solid #f9af4b;outline-offset:5px}.only-at-end{opacity:1;visibility:visible;pointer-events:auto}
.bt2074{position:fixed;left:25px;top:41%;width:95px;height:165px;background:transparent;color:#f3d4a2;display:flex;align-items:center;flex-direction:column}
.cord{display:block;width:3px;height:70px;background:linear-gradient(#ae8970,#ffdc9e);transform-origin:top;animation:cordSway 4.5s ease-in-out infinite}
.pull{font-size:12px;padding:9px 8px;background:#6e2039;border:1px solid #d49e79;border-radius:4px;writing-mode:vertical-rl;letter-spacing:.2em;min-height:61px;box-shadow:0 10px 20px #0005}
.tassel{width:16px;height:17px;border-radius:5px 5px 50% 50%;background:#cea66e}
.bt2074:hover .cord{height:42px}
.bt2074:hover .pull{background:#ba4a62;transform:translateY(-10px)}
@keyframes cordSway{50%{transform:rotate(4deg)}}
@media (max-width:700px){.bt2074{left:7px;top:38%;transform:scale(.85);transform-origin:bottom left}}
@media(prefers-reduced-motion:reduce){.tb-btt,.tb-btt *{animation-duration:.01ms!important;transition-duration:.01ms!important}}

(()=>{'use strict';const control=document.querySelector('[data-backtop]');if(!control)return;const reduced=matchMedia('(prefers-reduced-motion: reduce)');const footer=control.classList.contains('only-at-end');let busy=false;function refresh(){busy=false;const max=Math.max(1,document.documentElement.scrollHeight-window.innerHeight);const p=Math.min(1,scrollY/max);document.documentElement.style.setProperty('--page-progress',p.toFixed(4));if(!footer){const show=scrollY>145;control.classList.toggle('is-visible',show);control.tabIndex=show?0:-1;control.setAttribute('aria-hidden',String(!show));}const number=document.querySelector('[data-progress-number]');if(number)number.textContent=Math.round(p*100)+'%';}function onscroll(){if(!busy){busy=true;requestAnimationFrame(refresh)}}addEventListener('scroll',onscroll,{passive:true});addEventListener('resize',onscroll,{passive:true});control.addEventListener('click',()=>window.scrollTo({top:0,behavior:reduced.matches?'instant':'smooth'}));refresh();})();

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, performing arts and festivals.

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.