html,body{height:100%}body{display:flex;justify-content:center;align-items:center;margin:0;overflow-y:hidden}#paper-container{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}