.back-to-top{position:fixed;right:24px;bottom:24px;z-index:75;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;width:72px;height:64px;padding:8px 4px;border:1px solid #fff;border-radius:6px;background:#0756a8;color:#fff;box-shadow:0 3px 14px #00336633;font:14px/1.4 "Microsoft YaHei",sans-serif;cursor:pointer}
.back-to-top[hidden]{display:none}
.back-to-top:hover{background:#003e80}
.back-to-top:focus-visible{outline:3px solid #ff8a00;outline-offset:3px}
.back-to-top svg{width:22px;height:22px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
@media(max-width:900px){.back-to-top{right:12px;bottom:80px;width:68px;height:60px}}