zx-editor/docs/gitbook/gitbook-plugin-back-to-top-button/plugin.css

ZxEditor is a HTML5 rich text editor

.back-to-top{position:fixed;bottom:25px;right:25px;background:rgba(0,0,0,.5);width:50px;height:50px;display:block;text-decoration:none;-webkit-border-radius:35px;-moz-border-radius:35px;border-radius:35px;display:none}.back-to-top i{color:#fff;margin:0;position:relative;left:15px;top:14px;font-size:22px}.back-to-top:hover{background:rgba(0,0,0,.9);cursor:pointer}.book.color-theme-1 .back-to-top{background:rgba(112,66,20,.5)}.book.color-theme-1 .back-to-top i{color:#f3eacb}.book.color-theme-1 .back-to-top:hover{background:rgba(112,66,20,.9)}.book.color-theme-2 .back-to-top{background:rgba(189,202,219,.5)}.book.color-theme-2 .back-to-top i{color:#1c1f2b}.book.color-theme-2 .back-to-top:hover{background:rgba(189,202,219,.9)}@media only screen and (min-device-width:320px) and (max-device-width:480px) and (-webkit-min-device-pixel-ratio:2) and (orientation:portrait){.back-to-top{bottom:10px;right:10px}}