Zoom to bounding box

const width = 975;
const height = 610;

const zoom = d3.zoom()
    .scaleExtent([1, 8])
    .on("zoom", zoomed);

const svg = d3.create("svg")
    .attr("viewBox", [0, 0, width, height])
     .attr("width", width)
    .attr("height", height)
    .attr("style", "max-width: 100%; height: auto;")
    .on("click", reset);

const path = d3.geoPath();

const g = svg.append("g");

const states = g.append("g")
    .attr("fill", "#444")
    .attr("cursor", "pointer")
  .selectAll("path")
  .data(topojson.feature(us, us.objects.states).features)
  .join("path")
    .on("click", clicked)
    .attr("d", path);

states.append("title")
    .text((d) => d.properties.name);

g.append("path")
    .attr("fill", "none")
    .attr("stroke", "white")
    .attr("stroke-linejoin", "round")
    .attr("d", path(topojson.mesh(us, us.objects.states, (a, b) => a !== b)));

svg.call(zoom);

function reset() {
  states.transition().style("fill", null);
  svg.transition().duration(750).call(
    zoom.transform,
    d3.zoomIdentity,
    d3.zoomTransform(svg.node()).invert([width / 2, height / 2])
  );
}

function clicked(event, d) {
  const [[x0, y0], [x1, y1]] = path.bounds(d);
  event.stopPropagation();
  states.transition().style("fill", null);
  d3.select(this).transition().style("fill", "red");
  svg.transition().duration(750).call(
    zoom.transform,
    d3.zoomIdentity
      .translate(width / 2, height / 2)
      .scale(Math.min(8, 0.9 / Math.max((x1 - x0) / width, (y1 - y0) / height)))
      .translate(-(x0 + x1) / 2, -(y0 + y1) / 2),
    d3.pointer(event, svg.node())
  );
}

function zoomed(event) {
  const {transform} = event;
  g.attr("transform", transform);
  g.attr("stroke-width", 1 / transform.k);
}

display(svg.node());

const us = FileAttachment("data/us-states-albers-10m.json").json().then(display);