if (hexo-config('back2top.enable')) { .back-to-top { font-size: $b2t-font-size; if (not hexo-config('back2top.scrollpercent')) { span { display: none; } } if (hexo-config('back2top.sidebar')) { margin: 20px - $sidebar-offset -10px -20px; opacity: 0; transition: opacity $transition-ease; &.back-to-top-on { cursor: pointer; opacity: $b2t-opacity; &:hover { opacity: $b2t-opacity-hover; } } } else { bottom: $b2t-position-bottom; box-sizing: border-box; color: $b2t-color; padding: 0 6px; transition: bottom $transition-ease; sidebar-toggle(); if (not hexo-config('back2top.scrollpercent')) { width: 24px; } &:hover { color: $sidebar-highlight; } &.back-to-top-on { bottom: $b2t-position-bottom-on; } } } }