#logo{position:absolute;top:20px;right:20px;background-color:#fff;border:1px solid #d3d3d3;padding:5px;box-shadow:2px 2px 2px 1px #0000004d}#paper{margin:0 auto}.joint-tool[data-tool-name=button] circle{fill:#333}.joint-tool[data-tool-name=connect]:not(:hover){opacity:0}.active [joint-selector=line]{stroke:#4666e5}