@media (prefers-reduced-motion:reduce){*,::after,::before{transition:none!important;animation:none!important}}@media (prefers-contrast:more){.article-content pre,.info-box,.warning-box{border-left-width:6px}}@media (scripting:none){.cookie-banner,.cookie-modal,.reading-progress,.skeleton-wrap,.theme-button{display:none!important}.article-content{display:block}}.back-to-top{position:fixed;bottom:6rem;right:2rem;width:56px;height:56px;border-radius:50%;background:var(--bg-card);color:var(--text-primary);border:2px solid var(--border-subtle);display:flex;align-items:center;justify-content:center;box-shadow:0 4px 12px var(--shadow-md);cursor:pointer;z-index:998;opacity:0;pointer-events:none;transform:translateY(12px);transition:opacity .25s,transform .25s,border-color .2s,background .2s}.back-to-top.visible{opacity:1;pointer-events:auto;transform:translateY(0)}.back-to-top:hover{border-color:var(--accent-yellow);background:var(--bg-secondary);transform:translateY(-3px) scale(1.05);box-shadow:0 6px 16px var(--shadow-md)}.back-to-top.visible:hover{transform:translateY(-3px) scale(1.05)}.back-to-top:active{transform:translateY(-1px) scale(1.02)}.back-to-top:focus{outline:3px solid var(--accent-yellow);outline-offset:3px}.back-to-top:focus:not(:focus-visible){outline:0}.back-to-top i{font-size:1.5rem}html.theme-dark .back-to-top{box-shadow:0 4px 12px rgba(0,0,0,.4)}.back-to-top::before{content:attr(aria-label);position:absolute;right:calc(100% + 12px);background:rgba(0,0,0,.9);color:#fff;padding:8px 12px;border-radius:6px;font-size:.85rem;white-space:nowrap;opacity:0;pointer-events:none;transition:opacity .2s}.back-to-top:hover::before{opacity:1}@media (pointer:coarse){.back-to-top{width:64px;height:64px;bottom:5.5rem;right:1rem}}@media (max-width:600px){.back-to-top{width:48px;height:48px;bottom:5rem;right:1rem}}@supports (padding:env(safe-area-inset-left)){.back-to-top{bottom:max(6rem,calc(env(safe-area-inset-bottom,0px) + 6rem));right:max(2rem,env(safe-area-inset-right,2rem))}@media (pointer:coarse){.back-to-top{bottom:max(5.5rem,calc(env(safe-area-inset-bottom,0px) + 5.5rem));right:max(1rem,env(safe-area-inset-right,1rem))}}}@media (prefers-reduced-motion:reduce){.back-to-top{transition:opacity .25s;transform:none!important}}