Made borders much thicker, and changed the grey colour to be lighter

drawtriangle.js

@@ -112,7 +112,7 @@ svg.append("polygon")
   .attr("points", outerPoints.map(p => p.join(",")).join(" "))
   .attr("fill","none")
   .attr("stroke", colour)               // Outer line color
-  .attr("stroke-width", 3);                // Thin outer line
+  .attr("stroke-width", 9);                // Thicker outer line
 
 // Put label in bottom centre of triangle
 const bottomLeft = outerPoints[1];
@@ -126,7 +126,7 @@ svg.append("text")
   .attr("y", midY - 15)   // Alter for correct height
   .attr("text-anchor", "middle")
   .attr("fill", textcolour)    /// My Colour
-  .attr("font-size", "24px")
+  .attr("font-size", "22px")
   .attr("font-weight", "bold")
   .text(`${text}`);
 
@@ -136,7 +136,7 @@ svg.append("text")
   .attr("y", midY -60)
   .attr("text-anchor", "middle")
   .attr("fill", "black") // 🎨 customize color
-  .attr("font-size", "22px")
+  .attr("font-size", "24px")
   .attr("font-weight", "bold")
   .attr("font-family", "Courier New, monospace")
   .text(`${mean}`);