JSFiddle - React, Tailwind, and code Playground

HTML

<div id="myelement">  
</div>

JavaScript

var svg = d3.select('#myelement').append('svg'),
    curve = svg.append('path')
                 .attr('d', 'M0,200 C400,200 400,200 400,0')
                 .attr('stroke', '#fff')
                    .attr('fill-opacity', 0);

curve.transition()
       .attr('stroke', '#000')
       .attr('d', 'M0,200 C400,200 400,200 400,0')